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3 The Costs of Social Learning: Baka Childrens Daily Activities

3 The Costs of Social Learning: Baka Childrens Daily Activities

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4



A Multistage Learning Model for Cultural Transmission: Evidence from Three. . .



and the acquisition of LEK, we grouped children’s

reported activities in the following three clusters: (a) subsistence-related activities that favor the acquisition of

LEK (experiential learning), (b) activities indirectly related

to subsistence but that favor the acquisition of LEK as they

are indivisible from Baka’s culture (through the acquisition

and transmission of ethics, values, and cosmology) (contextual learning), and (c) activities that do not particularly favor

the acquisition of LEK as they subtract time devoted to the

previous categories (i.e., school or modern leisure). As the

notion of subsistence is debated (Schumann and Macinko

Table 4.1 Categorization of children’s activities

Category

Experiential

(direct)

learning



Sub-category

Hunting



Gathering

Agricultural

Work

Fishing

Handicraft



Contextual

(indirect)

learning



Domestic work



Playa



Traditional

songs, tales and

dances

Maintenance

No LEK

learning



School

Socializing with

Bantu

Listening to

music

Alcohol

drinking

Football

Other activities



a



Activities

Hunting small animals with traps;

hunting with sling, bow and

arrows, or stones; collective

hunting; hunting cable snares;

hunting with spear; unearth game

with smoke; wheel and “leka”

playing

Gathering of subspontaneous

and/or wild edibles products

Cleaning fields; planting or

harvesting agricultural products

in household’s or Bantu’s plots

Collective fishing with dams;

fishing with hook; fishing with net

Making toys in Raphia sp.;

building replicates of mongulu;

weaving mats and baskets

Fetching water; collecting

firewood; washing clothes/dishes;

sweeping house; cooking

Play with Baka children;

collective plays, such as hideand-seek, and marbles; solitary

plays as wheel/car pushing

Performing Baka’s songs and

dances; narrating tales; listening

to tales

Sleeping, resting, eating with

Baka

Attending school; doing

homework

Spending time with Bantu

children (play, chatting. . .)

Listening music



Football playing

Trade, hairdressing. . .



This category only includes play related to the contextual learning; play

related to experiential learning is included in the respective category



51



2007), here we consider subsistence activities as those that

procure essential elements for living, including both nutrition and shelter, and considering both getting and processing

the resources.

The activities that favor Baka children’s LEK acquisition, both by experiential and contextual learning, are

predominant in their daily life, taking an average of 7 h

per day (204 and 220 min per day, respectively). Domestic

work was the activity most frequently performed, both by

boys and girls, as it was mentioned in 93 % of the

interviews and it was also the most important activity in

terms of time invested, as children devoted an average of

136 min per day to domestic work. The following most

frequently mentioned activities were three experiential

learning activities: agricultural work, hunting, and

gathering, activities that were mentioned in almost 50 %

of the interviews. As previously shown (Kamei 2005), our

data suggest that playing is a major activity in children’s

daily life, also providing significant learning opportunities.

In our data, play that did not clearly involve experiential

learning was reported in 57.8 % of the surveys.

School and other activities where LEK is not usually

acquired are comparatively less frequent, with an average

of 138 min/day. Among the other activities that do not lead

to the transmission of LEK, listening to modern African hits

was reported in almost half of our observations (43.5 %),

taking an average of 55 min per day or about twice the

duration of school attendance.

Boys and girls showed no difference in the amount of

time spent engaging in most activities. Not surprisingly,

however, given the observed distribution of labor among

adults, hunting and hunting-related activities were clearly

predominant among boys (reported 70 % of the time by boys

vs. 24 % of the time by girls). Fishing and fishing-related

activities were clearly predominant for girls (who reported

fishing around 30 % of the observations vs. 15 % by boys).

The analysis of group composition during children’s

activities, confirmed by our own ethnographic experience,

suggests that children perform many activities without the

adults’ presence. Thus, according to our data, children spend

large portions of time only with other children and without

adult supervision (Table 4.2). Among the activities in which

experiential and contextual learning can occur, the presence

of adults varies. The presence of adults was relatively high in

fishing and agricultural work, where 33.6 % and 47.5 % of

the people accompanying children were adults. This is in

sharp contrast with the almost complete absence of adults

during hunting activities: on average only 8.8 % of the

people accompanying the respondent child to hunting

activities were adult.



V. Reyes-Garcı´a et al.



52

Table 4.2 Children’s use of time and adult’s involvement in children’s

activities

Times the

activity

was listed

(n ¼ 232) Minutes

devoted to

activity

Category

Sub-category N

%

Experiential Hunting

115 49.6 42

learning

Gathering

113 48.7 47

activities

Agricultural

80 34.5 66

work

Fishing

50 21.6 43

Handicraft

21 9.1

6

Total Experiential learning

204

activities

Contextual

Plays

134 57.8 40

learning

Traditional

29 12.5 12

activities

songs, tales

and dances

Maintenance

49 21.1 32

Domestic

215 92.7 136

work

Total Contextual learning

220

activities

No LEK

School

52 22.4

learning

Socializing

22 9.5 20

activities

Listening to 101 43.5 55

music

Alcohol

32 13.8

2

drinking

Football

33 14.2 13

Other

38 16.4

4

activities

Total No LEK learning

138

activities



Number of

people

accompanying

the respondent

% of

Meana adults

0.49

8.8

1.97

22.0

1.53

47.5

2.50

1.43



33.6

6.7



1.02

2.69



5.1

19.2



1.04

0.41



29.4

21.5



0.17

1.41

1.18



0

16.1

32.5



0.25



37.5



1.61

1.24



1.9

0.2



a



The average of people accompanying the respondent was calculated

with the total of activities performed (N)



Although a first look at Table 4.3 suggests that time

invested in the different categories does not vary as children

move into adolescence, the activities children perform do

indeed shift, as has been shown in previous research with

hunter-gatherer societies (Ruiz-Mallen et al. 2013). For

example, in the category of activities in which transmission

of LEK is not favored, school attendance decreases, whereas



time invested in other activities such as listening to music

and socializing with Bantu neighbors increases as children

move into adolescence. Similarly, as children age there

appears to be a shift in preferences from hunting and fishing

to gathering and agriculture. Those changes could be

motivated by the involvement in wage-earning activities.

Moreover, our field experience suggests that important

changes do occur during that time in relation to the actual

practice of the activity, its location, or the tools used. For

example, while children in middle childhood hunt using

traps for mice and birds, adolescents, however, prefer the

collective hunting of small mammals using smoke and with

spears.

Table 4.3 Minutes invested in the different activities, by age

categories



Category

Experiential

learning

activities



Sub-category

Hunting

Gathering

Agricultural

work

Fishing

Handicraft

Total experiential learning

activities

Contextual

Traditional play

learning

Traditional

activities

songs, tales, and

dances

Maintenance

Domestic work

Total contextual learning

activities

No LEK

School

learning

Socializing

activities

Listening to

music

Alcohol

drinking

Football

Other activities

Total no. of LEK learning

activities



Middle

childhood

Mean

SD

53.83

64.43

33.71

50.75

54.49

94.51



Adolescents

Mean

SD

23.64

45.56

66.58 111.57

88.26 132.80



50.59

4.57

197.29



114.18

17.51



28.91

7.83

215.22



87.32

25.79



42.66

11.91



41.48

31.05



30.33

12.39



48.81

44.95



19.30

142.42

216.29



54.99

110.03



48.91

136.58

228.21



105.63

111.55



48.36

11.60

47.11



91.69

72.17

67.04



16.52

33.75

69.46



55.95

96.08

77.15





16.88

10.78

134.73





42.69

29.02





10.05

19.35

149.13





31.64

45.45



4



A Multistage Learning Model for Cultural Transmission: Evidence from Three. . .



Similarly, and as reported elsewhere (Bird and Bliege Bird

2005), the type of products children collect, the purpose of

gathering, and the location of the activity change with age.

While Baka children in early and middle childhood typically

gather and consume tubers of peripherally disseminated agricultural plants, such as potatoes and some Araceae around the

village, adolescents gather both wild edibles, such as Koko

leaves (Gnetum africanum) for household consumption, and

other forest products (e.g., seeds of Baillonella toxisperma,

Pentaclethra macrophylla) for sale. One important aspect that

facilitates this shift relates to the fact that, as previously

shown by Hagino and Yamauchi (2013), older children can

go deeper into the forest. A similar case was observed during

collective fishing expeditions. Baka fishing entails blocking a

part of the stream with dams of clay trunks and branches and

then bailing out most of the water, so they can collect trapped

fish and shellfish. Although during such fishing expeditions

adults, adolescents, and children go together, their activities

differ. Whereas adults and adolescents build dams, bail out

the water, dig into the banks, and finally collect the trapped

fish, children are walking around, digging and looking for fish

on their own. It is worth noticing, however, that during the

activity children have the opportunity to observe the whole

operation and gradually get involved in more complex tasks.



4.4



Transmission of Cultural Knowledge

Across the Life Cycle Among the Jenu

Kuruba



Building on results from our first case study, in this second

case, we explore the processes of cultural transmission that

create variation in local ecological knowledge and skills

throughout the life cycle. Since human life spans are long

relative to the period of data collection, we present crosssectional data of learning patterns.

The Jenu Kuruba is a government-designated forest-dwelling scheduled2 tribe living in and around the dry deciduous

forests in southern Karnataka, India. Those who continue to

reside in forested areas combine wage labor on local agricultural estates with household cultivation and seasonal collection of forest products for consumption or sale. The Jenu

Kuruba specialize in collecting wild honey, a culturally preferred and economically profitable activity.3 Honey collecting

has been a stable skill set in the studied communities over the

last 150 years (Demps et al. 2012a), and we have little reason

to believe that transmission patterns have changed drastically



2

“Scheduled” here refers to historically disadvantaged castes and tribes

recognized by the Indian constitution.

3

A day’s wages from laboring on local coffee estates is worth about

1–1.5 kg of forest honey; hives produce 1–30 kg depending on the bee

species.



53



over the last two generations, despite important changes in

other aspects of their life. Age and gender form the major

structural hierarchies among the Jenu Kuruba at this site, and

honey collection is a preferably male activity. Adults are

very tolerant regarding boys’ independence and rarely

insist they adopt particular behavioral repertoires such

as school attendance or honey collecting. Despite this tolerance toward boys, girls – especially after puberty – are

expected to remain near the household outside of school and

must not wander in the forest without a chaperone. Women do

not collect honey except for very rare opportunistic events.

We conducted ethnographic work through participant

observation and structured and unstructured interviews in

five villages over 11 months (from January to December

2009). We chose a cluster of five villages (~500 people) to

achieve a large sample size within close proximity of the

forest. Our study villages were located in a reserve forest

where people have access to honey. Ethnographic work, participant observation, and unstructured interviews provided

information on honey collection and the context of learning.

Multidimensional interviews allowed us to measure the accumulation of honey-collecting knowledge in males from the

age of 6 years old until death. Informants responded to

questions about honey-collecting knowledge, experience,

learning behavior, and demographic information. We

included a measure of theoretical knowledge or information

about honey and bees that could be verbalized – such as what

types of plants the bees eat from, what types of honey are

found in the forest, and where and what the social structure of

the hive is. Responses were used to create a theoretical LEK

score out of a total of 14 points for each individual.4 We also

asked informants to self-report the age at which a set of skills

was learned and then mastered, as well as the perceived path

(observation, teacher, or hands-on) for the acquisition of skills

required for tree climbing, making smoky torches, cutting

honey combs, and singing a honey-collecting song, all

activities reported as essential tools for successful honey

collection. When individuals responded that they were taught

or had observed someone to learn a skill, we recorded from

whom they reported learning.

During the biannual honey seasons, four types of bees

produce honey in the local forest: two small stingless species

(Trigona spp., Apis florea), a midsized bee similar to the

Western honeybee (Apis cerana), and the giant Asian bee

(Apis dorsata). Honey extraction for all four types of bees

require skill in locating hives, but the last two species require

additional skills for extraction such as making smoke and

cutting honeycombs. A. cerana makes combs inside tree

trunks and old anthills. Collectors can minimize stings by

producing a small amount of smoke (often from a cigarette)



4

All theoretical LEK questions were pretested in an independent sample for clarity and to achieve a mix of difficulties of responses.



54



and smooth, slow hand movements in cutting and extracting

combs. A. dorsata combs hang from large branches in tall

trees and require competencies in tree climbing and creating

smoky torches that will produce heavy, continual smoke to

subdue the bees. Ritualistic knowledge in the form of

prayers and songs is also important to ensure a successful

collection event from A. dorsata.

Children spend most of their time either around the household, among groups of closely aged same-sex children in their

village, or at the local school. School attendance up to grade

seven is promoted, but not mandatory. There is some evidence

that children who play truant 6 or more days a month see a

moderate increase in LEK related to honey collecting. Children allocate time not spent in school to playing with their

peers. A favorite game to play in the forest on the way home

from school is “tree monkey”– where a boy who is “it” chases

the others about in the branches of smallish trees. Men are

tolerant of boys accompanying them on honey-collecting

expeditions and will sometimes incorporate aspects of teaching during the trip.

Results from our structured interviews suggest that,

although the amount and type of knowledge varied greatly

between individuals, most theoretical knowledge (i.e., information about honey and bees that can be verbalized) is

acquired by the mid-twenties (Fig. 4.1). Most basic skills

(tacit knowledge) are also learned before the mid-twenties

(Fig. 4.2). Knowledge and skill at honey-collecting activities

is honed until physical and then mental abilities begin

decreasing with age.

Fig. 4.2 Mosaic plots

representing comparisons

between social learning strategies

for different skills by age cohort.

Sample sizes marked for each

category, a dashed line indicates

zero responses, and present but

not labeled had one response



V. Reyes-Garcı´a et al.



Fig. 4.1 Explicit knowledge score for males, including all boys aged

6–15 and adults 16 and older who have reported honey-collecting

experience (n ¼ 147). The solid line represents a cubic polynomial

for male knowledge scores across age. The dashed line represents a

spline of female knowledge scores (points not plotted here). Female

knowledge scores act as a baseline and allow us to infer a longitudinal

trend with a cross-sectional data set (n ¼ 39)



4



A Multistage Learning Model for Cultural Transmission: Evidence from Three. . .



Figure 4.2 shows that age affects social learning

strategies. Each mosaic plot pictures self-reported social

learning patterns and the age at which an individual first

learned that skill. Column widths represent the proportion of

individuals learning a skill in that age category. Most boys

learn to climb trees between 6 and 9 years old. Only one

person reported learning this skill after the age of 22. Most

boys learned to make smoky torches from 10 to 15 years old

and to cut honeycombs by 16–21 years. Individuals rely less

on close kin as they reach adolescence, shifting to horizontal

and oblique learning, i.e., friends and older individuals.



In a cross-cultural review of the acquisition of hunting skills

across the life cycle, MacDonald (2007, p. 397) concludes that,

“a wide range of people are involved in different parts of a

child’s hunting education, and there is considerable variation

from group to group in the people concerned.” So too is honeycollecting LEK reported as acquired sequentially from a variety of sources, with an emphasis on learning during childhood

and adolescence. Vertical transmission is clearly important for

this body of LEK, but is not dominant as the abilities and

social contexts of children change with age.



4.5



Fig. 4.3 Self-reported demonstrators for socially learned honeycollecting skills. Column widths represent proportion of responses for

each skill category and sample sizes are labeled inside each box. Data

from individuals aged 6 years and up who report knowing the skills



Figure 4.3 also shows that modes of transmission vary

greatly depending on types of knowledge and costs of

learning. Some knowledge and skills lend themselves more

easily to certain modes of learning (Fig. 4.3). Tree climbing

was acquired mainly through practice with peers in games

like “tree monkey” and play in the forest, although almost a

third of individuals who acquired this skill reported learning

through observation or teaching. Many practical skills, like

tree climbing, can only be mastered through training (Gurven

et al. 2006). Playing a game with peers is a low-cost way to

improve this skill set. Alternately, adult experts might provide

feedback or suggest better techniques, which the novice then

may incorporate. Other skills, like singing a ritualistic song,

must be observed or taught from other individuals, who

sometimes might only teach in specific contexts.



55



Cultural Transmission Among Tsimane’

Adults



Our last case study attempts to estimate how the multistage

learning model results in the distribution of knowledge at

adulthood. If cultural transmission models are dynamic and

the preferred model shifts at different periods of the life cycle,

then, there is no reason to expect that a person’s knowledge

would mostly be associated with (a) the same-sex parent, as it

would be if vertical transmission was predominant, nor with

(b) individuals from the parental cohort other than the parents,

as it would be if oblique transmission was predominant, or

with (c) age peers, as it would be if horizontal transmission

was predominant. To test this idea, our third case study

examines the resulting outcome, in terms of relative influence,

of the impact of different pathways for the transmission of

knowledge in configuring an adult knowledge.

The study was conducted among the Tsimane’: a huntergatherer society in the Bolivian Amazon. At present, the

Tsimane’ number is about 12,000 and they live in more than

100 villages, mostly in the province of Beni, Bolivia (ReyesGarcı´a et al. 2012b). The Tsimane’ economy centers on hunting, fishing, and slash-and-burn farming, with cash cropping of

rice becoming a dominant form of monetary income (Vadez

et al. 2008). The Tsimane’ also sell or barter agricultural and

non-timber forest products in nearby towns or with traveling

traders who come to their villages. Fairly autarkic until the

1950s, over the last decades, the Tsimane’ have increasingly

engaged in wage labor for forest concessions, illegal loggers,

colonist farmers, and cattle ranchers operating within or in the

vicinity of their territory (Reyes-Garcı´a et al. 2012a).

To study the relative weight of vertical, oblique, and

horizontal transmission in adult’s knowledge, we selected a

culturally important trait for a hunter-gatherer society:

ethnobotanical competence, differentiating between



V. Reyes-Garcı´a et al.



56



ethnobotanical knowledge and skills (McDade et al. 2007;

Reyes-Garcı´a et al. 2008a). We obtained individual level

measures of ethnobotanical knowledge and kinship information of informants in the sample. With such information, we

were able to estimate the association between a person’s

knowledge and the knowledge of the person’s (a) same-sex

parent, (b) individuals from the parental cohort other than

the parents, and (c) age peers. The descriptive statistics of

the variables used in the multivariate analysis can be found

in Table 4.4. We use same-sex parent knowledge, and not

average parental knowledge, because the division of labor

among the studied population follows sex lines. For the

empirical analysis, we draw upon primary data collected

from 270 adults (!16 years of age) in 13 villages. Data

include separate individual-level scores of ethnobotanical

knowledge and skills for a sample of adults related by

kinship (parents and their offspring) and by spatial and

temporal proximity (birth date and village of residency).

The empirical analysis provided four insights on the

resulting effects of the influences of different transmission

modes before adulthood. First, although vertical transmission is important, the relative weight of oblique transmission

is predominant. Second, the relative weight of horizontal



transmission is low. Third, we find gendered differences in

the transmission of ethnobotanical knowledge. And four, we

find differences in the path of transmission for ethnobotanical knowledge and skills.

Thus, our first finding was that our proxies for same-sex

parental ethnobotanical knowledge were consistently

associated with offspring knowledge, which corroborates

the finding that parents play an important role in the transmission of cultural knowledge (Hewlett and Cavalli-Sforza

1986; Lozada et al. 2006; Ohmagari and Berkes 1997).

Importantly, our data show that the relative weight of the

vertical transmission pathway is still evident once the person

reaches adulthood. However, our findings suggest that the

association is small in real terms. Doubling same-sex parental ethnobotanical knowledge (an unlikely event) would only

result in a 2 % increase of offspring ethnobotanical knowledge and a 3 % increase of offspring ethnobotanical skills

(Table 4.5). The magnitude of the association for parentalcohort ethnobotanical knowledge is larger than the magnitude of the association for same-sex parental ethnobotanical

knowledge, suggesting that the weight of the oblique transmission path is larger than the weight of the vertical path, at

least for ethnobotanical knowledge.



Table 4.4 Definition and descriptive statistics of variables used in regression analysis (n ¼ 270)

Variable

I. Outcome variable

Ethnobotanical knowledge

Ethnobotanical skills

II. Explanatory variables

Same-sex parent

ethnobotanical knowledge

Age-peer ethnobotanical

knowledge

Parental cohort

ethnobotanical knowledge

Same-sex parent

ethnobotanical skills

Age-peer ethnobotanical

skills

Parental cohort

ethnobotanical skills

III. Control

Male

Age

Schooling



Definition



Mean



Score in test of plant knowledge; subjects were asked if they knew names of 15 wild and

semidomesticated plants. In regression entered in natural logarithms

Reported use of 12 wild and semi-domesticated plants. In regression entered in natural

logarithms



11.61



2.78



4.39



2.68



3.13



2.15



12.15



2.04



13.08



1.61



4.39



2.68



4.59



1.42



6.04



1.57



0.44

27.31

2.62



0.49

11.15

2.10



Number of matches in responses to the ethnobotanical knowledge test between a person and

his/her same-sex parent

Average ethnobotanical knowledge score of people who were born the same or Ỉ4 years apart

from the subject’s year of birth and who lived in the same village during childhood (excluding

subject’s knowledge)

Average ethnobotanical knowledge score of people who were born between 20 and 40 years

before the subject and who lived in the subject’s village of childhood, excluding parental

knowledge

Number of matches in responses to the ethnobotanical skill test between a person and his/her

same-sex parent

Average ethnobotanical skills score of people who were born the same or Ỉ4 years apart from the

subject’s year of birth and who lived in the same village during childhood (excluding subject’s

knowledge)

Average ethnobotanical knowledge score of people who were born between 20 and 40 years

before the subject and who lived in the subject’s village of childhood, excluding parental

knowledge

Sex of the subject, Male ¼ 1

Age in years

Maximum school grade achieved by subject



SD



4



A Multistage Learning Model for Cultural Transmission: Evidence from Three. . .



57



Table 4.5 Regression results: Paths of the transmission of ethnobotanical knowledge and skills, Tsimane’ adults

Dependent variables

A. Ethnobotanical knowledge (log)

[a]

Male

Explanatory variables

Same-sex parent skills (log)

0.025**

Age-peer knowledge (log)

Parental cohort knowledge

(log)

Control variables

Male

Schooling

Age

Constant

R2

N



B. Ethnobotanical Skills (log)

[b]

Female



[c]

Pool



0.023**



0.022***



À0.314

0.618***



0.235

0.372*



À0.074

0.373**



^

À0.009

0.008***

1.154

0.58

123



^

À0.021

À0.004**

0.653

0.55

147



0.078***

À0.015*

0.006**

1.44***

0.54

270



Same-sex parent knowledge

(log)

Age-peer skills (log)

Parental cohort skills (log)



[a]

Male



[b]

Female



[c]

Pool



À0.010



0.073***



0.038**



À0.186

0.460*



À0.121

À0.160



À0.198

À0.008



^

À0.054***

0.013**

1.083

0.38

123



^

À0.051

.003

1.514

0.40

147



0.146**

À0.055***

0.009**

1.442**

0.33

269



***, **, and * significant at 1 %, 5 %, and 10 %. Regressions are ordinary-least squares. Robust standard errors used when probability of

exceeding χ 2 value in Breusch-Pagan test <5 %. ^ ¼ variable intentionally left out. Regressions contain a full set of dummy variables for village of

residency (not shown). For definition of variables, see Table 4.1



This explanation would also work for our second finding,

that the relative weight of horizontal transmission is low. As

we have seen, several authors have argued that there are

social and evolutionary reasons to expect intragenerational

transmission of cultural knowledge (Boyd and Richerson

1985; Harris 1999; Lancy 1999; Zarger 2002). However,

our data from the two previous case studies suggest that

during childhood children turn to peers because they are

low-cost teachers, with the caveat that they can only teach

basic skills and knowledge. Children might learn from their

peers, but they probably mostly learn basic competencies in

a given cultural context, which might not reflect in the type

of association we examined here, which is biased toward

detecting associations in more specialized knowledge.

The third finding of our work relates to the gendered

differences in the transmission of ethnobotanical knowledge

among men and women, the differences being stronger for

the transmission of ethnobotanical skills than for the transmission of ethnobotanical knowledge. Knowledge of the

parental cohort is generally associated with offspring ethnobotanical knowledge, but only for the women in the sample

are the skills of the parental cohort associated to offspring

skills. Why would the paths for the transmission of ethnobotanical knowledge and ethnobotanical skills among

Tsimane’ men and women differ? Differences in the transmission paths of ethnobotanical knowledge and skills among

Tsimane’ men and women might reflect differences in time

allocation and sexual division of labor among the Tsimane’.

From a young age, Tsimane’ girls are expected to perform

household tasks and accompany mothers and other relatives

to agricultural fields. Such close interaction could facilitate



the transmission of ethnobotanical knowledge and skills

from the older to the younger generation. In contrast,

Tsimane’ men are reluctant to take young children to the

forest with them because of the dangers of the forest for

young children and because children might make noise, thus

spoiling hunting opportunities. This could result in boys

having fewer opportunities to directly interact and learn

from their fathers. Thus, it is possible that Tsimane’ men’s

learning from parents is of a more indirect nature than

Tsimane’ women’s learning from mothers. Because men’s

learning from parents is more indirect, it could be

superseded more easily by parental cohort knowledge.

Our last finding is that there are differences in the transmission paths for ethnobotanical knowledge and skills. This difference might relate to the different characteristics of those

two types of knowledge. Research shows that ethnobotanical

knowledge, such as names or traits used for recognition, is

mainly acquired during childhood and is easier to acquire than

ethnobotanical skills. Knowledge relies on cumulative memory and individuals can learn quickly and effectively through

relatively few interactions; therefore, individuals can acquire

ethnobotanical knowledge from many sources. The acquisition of complex skills might require higher investment by the

learner, as the process is more costly in time and requires a

number of direct observations and repetition within a particular ecological context. Individuals might be more conservative

in selecting models for acquiring skills and place more weight

on information acquired from older informants or informants

with more expertise than their peers, which might explain the

different pathways on the transmission of knowledge and

skills.



V. Reyes-Garcı´a et al.



58



4.6



Discussion and Conclusion



We organize our discussion around the evidence to support

the multistage learning model for cultural transmission,

emphasizing the importance of the social learning that

occurs during childhood and how this might be a prerequisite

for the acquisition of complex skills through scaffolding and

integration of information from multiple models. Overall,

the three case studies presented give support to the multistage learning model according to which individuals first

acquire information from their close social and ecological

environment and later update it with information from other

sources. Specifically, our case studies among the Baka and

the Jenu Kuruba provide some interesting insights in the

acquisition of cultural knowledge during childhood and adolescence, particularly emphasizing the role of vertical and

horizontal transmission, whereas our case study among the

Tsimane’ suggest that adult knowledge seems to result from

a combination of different sources, emphasizing the importance of oblique transmission in shaping an adult’s

knowledge.

The Jenu Kuruba case study illustrates the importance of

vertical transmission. Vertical transmission was reported as

important for acquiring many of the early skills and knowledge required for collecting honey. Anthropologists have

often stated the importance of vertical transmission;

although there is a growing agreement that vertical dominance might not be based on preference, but on contextual

elements including the type of knowledge being transmitted

and the age of learning. But, while parents should be the

most motivated individuals to provide accurate, profitable

learning opportunities to their offspring (Boyd and

Richerson 1985), it would be surprising to find that

individuals other than parents did not influence cultural

transmission, as allomaternal care is a pronounced human

trait (Hrdy 2009). Therefore, once individuals begin spending more time away from a parent’s care, they begin

accessing more varied types of demonstrators, who they

can use to update previously acquired knowledge. We

observed Jenu Kuruba boys accessing a variety of cultural

demonstrators according to their individual situations. Close

kin, distant kin, and neighbors were variously accompanied

on honey collecting trips and most Jenu Kuruba are very

tolerant of the presence of novices and will even point out

interesting or important ecological information.

The Baka case study illustrates the importance of horizontal transmission. Thus, during fieldwork, we observed

that Baka children engage in many activities, including

hunting, gathering, and fishing, without the presence of

adults. Such finding dovetails with studies in developmental

psychology stressing the importance of age peers in the

acquisition of knowledge and socialization, even in school

(Shaeffer 1996; Vygostky 1978). Time allocation studies



with children also show that children spend large portions

of time with siblings and age peers (Weisner and Gallimore

1977; Whiting and Whiting 1975). Time spent together

gives children the opportunity to share knowledge. Time

spent together also allows for staggered learning because it

allows children to learn from someone who knows just a

little more than themselves and is not necessarily an expert.

It might be easier to learn from these individuals than it

would be to learn from an adult because adults might be

less accessible, might move quickly over things because of

their expertise, and might be less willing to deal with the

naăve learner (Maynard and Tovote 2010). Thus, age-peer

groups may play an important role for practicing skills in a

social environment where scaffolding can occur. Initially

simple, but increasingly complex, activities provide novices

with the training and physical skills needed for the mastery

of cultural knowledge. Young children seem to spend a lot of

time together performing activities that train them in locally

required skills, such as hunting, fishing, collecting honey,

and learning about plants. For example, Baka adolescents or

young adults might join adult-hunting expeditions, in which

they would first be in charge of carrying the game and

increasingly being given other tasks. Similarly, among the

Jenu Kuruba, male kin are important teachers of honey

collecting, as these individuals are easy to access and generous with their time for novice honey collectors.

Interestingly and importantly as age-peer transmission can

be for scaffolding, the Tsimane’ case study suggests that the

relative weight of horizontal transmission is low for an adult

sample, as adults have already acquired more specialized

knowledge. This can be explained by the fact that, when the

learner has acquired the basic competencies from friends

(horizontal transmission) and family (vertical transmission),

then he or she is ready to shift to more expert teachers, who

might then also be willing to invest their time in a more

competent learner. Thus, the Tsimane’ case study seems to

suggest that oblique transmission is particularly important in

shaping an adult’s knowledge. This might be so because the

Tsimane’ social organization provides ample opportunities to

interact with same and older age kin and friends even from a

young age (Ellis 1996) and because Tsimane’ nowadays are

experiencing a rapidly changing social context (Reyes-Garcı´a

et al. 2013), a situation that favors reliance on oblique rather

than vertical transmission (McElreath and Strimling 2008).

Nevertheless, it is important to notice that the relative weight

of oblique transmission in adult’s knowledge does not refute

the importance of vertical nor of horizontal transmission.

Vertical and horizontal learning might still be important in

providing the baseline of an individual’s cultural knowledge;

however, for a sample of adults, evidence of vertical and

horizontal learning might be difficult to trace, as it might

have been shadowed by later updates that take place when

more specialized learning occurs.



4



A Multistage Learning Model for Cultural Transmission: Evidence from Three. . .



In conclusion, the two main findings from this work are

(1) that adult’s knowledge seems to result from a combination of different sources throughout the life span and (2) that

childhood is a critical period for social learning, as it is

during childhood when the baseline for the acquisition of

cultural knowledge and skills is set. In that sense, discussing

social learning in terms of vertical, horizontal, or oblique

pathways can set up false dichotomies. Many traits displayed

in adulthood are acquired as a result of a combination of

horizontal, vertical, oblique, and probably other pathways.

Vertical transmission may be important earlier in life, when

children spend more time around parents in the home and

when parents are more likely to give children early training

in basic skills and knowledge. Even at young age, children

can use their age groups to practice these basic skills and

knowledge. As children reach adolescence and begin spending more time with individuals from outside the home,

horizontal and oblique learning can serve to complement,

or in some cases substitute, previously gained knowledge.

Through scaffolding, skills and knowledge learned from

parents during childhood can be honed later on with peers

and non-kin experts. Ultimately, elements in the adult cultural knowledge kit will most likely be a mix of information

gathered from a variety of sources.

Acknowledgments Research was funded by grants from the Cultural

Anthropology Programs, NSF (BCS-0322380 for the Tsimane’ case

study and BCS-0726612 for the Jenu Kuruba case study), and the

European Research Council, Starting Grant ERC (FP7-261971-LEK),

for the case study on the Baka. We thank the Crop Physiology Lab at

International Crop Research Institute for the SemiArid TropicsPatancheru for providing office facilities to Reyes-Garcı´a. Thanks

also go to the Baka, the Jenu Kuruba, and the Tsimane’ for their

patience, friendship, and continuous support.



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5



To Share or Not to Share? Social Processes

of Learning to Share Food Among Hadza

Hunter-Gatherer Children

Alyssa N. Crittenden



Abstract



The importance of food sharing is tacit in evolutionary models of life history, family

formation, and altruism, yet the ontogeny of such behaviors is not well understood.

Given that childhood is argued to be the time when other-regarding preferences and

egalitarianism develop, it is critical to evaluate how the development of food sharing

may influence prosociality. In this chapter, the social processes of learning to share food

among Hadza hunter-gatherer children are explored. I combine naturalistic observations of

food sharing, experimental data on other-regarding preferences, and ethnographic interview data to determine processes of cultural transmission. The results suggest that Hadza

children routinely share food with both related and unrelated partners, although preferentially share with kin. They exhibit many processes of social learning, including observation,

imitation, participation, reinforcement, play, and teaching. These data support recent

suggestions that prosociality and egalitarianism develop strongly during middle childhood

when children acquire the normative rules of their society.

Keywords



Hadza  Hunter-gatherers  Social learning  Sharing



5.1



Introduction



While many species engage in the “trafficking” of food

(Winterhalder 1997), the degree and complexity to which

humans engage in this practice is categorically different and

is considered to be one of the hallmarks of human evolution

(Isaac 1978). While there remains considerable debate

regarding the motivation to share (Blurton Jones 1984;

Gurven 2004; Hawkes 1991; Jaeggi and Gurven 2013), it is

well established that sharing food may facilitate the development and maintenance of social bonds or minimize

differences in consumption (Hames and McCabe 2007;

Kaplan et al. 1985). While the significance of food sharing



A.N. Crittenden (*)

Department of Anthropology, University of Nevada Las Vegas,

Las Vegas, NV, USA

e-mail: alyssa.crittenden@unlv.edu



is routinely emphasized in evolutionary models of life history and family formation, the ontogeny of such behaviors is

often overlooked in theoretical models or discussion (see

Silk and House 2011 for a notable exception). Our characteristically long, slow, and intricately dynamic stage of

childhood is a fundamental defining characteristic of our

species’ life history (Bogin 1999). As childhood is increasingly considered to represent the developmental stage when

other-regarding preferences develop (Fehr et al. 2008, 2013;

House et al. 2013), it is necessary to begin incorporating

children into our evolutionary models in order to more fully

understand how the development of food sharing may influence the development of prosociality (Crittenden 2014a;

Crittenden and Zes 2015). Hunter-gatherers participate in

widespread food sharing on a daily basis, making them

ideal populations for exploring social aspects of food sharing. This chapter will explore processes of social learning

among Hadza child foragers of Tanzania and address the



# Springer Japan 2016

H. Terashima, B.S. Hewlett (eds.), Social Learning and Innovation in Contemporary Hunter-Gatherers,

Replacement of Neanderthals by Modern Humans Series, DOI 10.1007/978-4-431-55997-9_5



61



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