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Co-Residence Patterns in Hunter-Gatherer Societies Show Unique Human Social Structure

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Contemporary humans exhibit spectacular biological success derived from cumulative culture and cooperation. The origins of these traits may be related to our ancestral group structure. Because humans lived as foragers for 95% of our species' history, we analyzed co-residence patterns among 32 present-day foraging societies (total n = 5067 individuals, mean experienced band size = 28.2 adults). We found that hunter-gatherers display a unique social structure where (i) either sex may disperse or remain in their natal group, (ii) adult brothers and sisters often co-reside, and (iii) most individuals in residential groups are genetically unrelated. These patterns produce large interaction networks of unrelated adults and suggest that inclusive fitness cannot explain extensive cooperation in hunter-gatherer bands. However, large social networks may help to explain why humans evolved capacities for social learning that resulted in cumulative culture.
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Supporting Online Material for
Co-Residence Patterns in Hunter-Gatherer Societies Show Unique Human
Social Structure
Kim R. Hill,* Robert S. Walker,* Miran Božičević, James Eder, Thomas Headland, Barry Hewlett,
A. Magdalena Hurtado, Frank Marlowe, Polly Wiessner, Brian Wood
*To whom correspondence should be addressed. E-mail: kim.hill@asu.edu (K.R.H.); walkerro@missouri.edu (R.S.W.)
Published 11 March 2011, Science 331, 1286 (2011)
DOI: 10.1126/science.1199071
This PDF file includes:
Materials and Methods
SOM Text
Figs. S1 to S12
Tables S1 to S3
References
Supplementary Online Material- Coresidence patterns in hunter-
gatherer societies show unique human social structure
Supplementary Methods
Sample. Data for 24 hunter-gatherers societies with sufficient sample sizes were taken
from the Group Compositions in Band Societies (GCBS) data base compiled by
Woodrow W. Denham
(http://www1.aiatsis.gov.au/exhibitions/AlyaWeb/public/gcbs.html). Other data are either
unpublished (Ache, Hiwi, Agta, Hadza, Aka, Batak) or come from published primary
sources (Gunwinggu, Paliyan, Hill Pandaram, Ju/’hoansi). The complete sample consists
of 5,067 adults living in 323 different residential bands. See Table S1 for complete list of
all ethnographic groups, data sources and sample sizes. When age data were available,
adults were defined as individuals over the age of 15 years. In the absence of age
information, adults were defined as individuals listed as married, divorced, or widowed,
or taken at face value when “adults only” censuses were provided.
Residential units called “bands” include all members who slept within a 5 minute
walk of each other. Each band census provided a full accounting of all adults present in
that band on the day of census (including visitors and short term residents). These bands
were not land holding groups, but were generally economically self-supporting and self-
constituted. All societies in the sample had traditionally been foragers, and were partially
or fully dependent on hunting and gathering for subsistence at the time of census. In cases
where multiple censuses were conducted at least 6 months apart, each census was treated
as an independent data point, regardless of whether collected by one researcher or
multiple researchers. The Inuit societies were analyzed as independent data points given
their high variability in residence patterns.
Because only a small number of studies exist that provide data on members of
hunter-gatherer residential units and the genealogical links amongst all members, it was
not feasible to construct a random sample or stratified sample representing different
world regions. Instead, we included all known hunter-gatherer studies that contained the
required information and for which we could access the raw census data. In addition to
our diverse group of authors specializing on hunter-gatherers around the world, we
contacted outside experts in some world areas in order to determine if there were
additional ethnographic studies with coresidence data that we had overlooked (thanks to
Peter Gardner, Kirk Endicott, Ian Keen, Nick Peterson, Eric Smith). Minimally each
study population in our sample had multiple residential group censuses that listed all
adult members (with sex) and specified the genealogical relationships between them.
Only the Ache and Ju/’hoansi samples were based on more than 20 residential bands.
More complete studies also listed children, and provided sex and ages for all individuals.
All sample studies listed spousal and parent-offspring relationships as part of the census
protocol.
Ache and Hiwi residential bands were obtained through informant interview cued
by “random” events (see Hill and Hurtado 1996 for further details). This allows for
analyses of pre-contact band structure, but also presents the possibility of recall bias.
Middle-aged adults were interviewed between 1984-2004 to list all members of the band
in which they had resided when a particular “random” event took place in the 1958-1970
pre-contact period. These events included strange accidents (somebody hit by lightning,
eaten by jaguar, fell out of tree, etc.), the killing of rare game items (giant otter, giant
armadillo, blue macaw, etc.), or unpredictable life history events (birth, death, or first
menses). The ability of informants to recall band membership has been verified with
interviews about observed foraging bands in the 1990s (McMillan 2001) but some recall
bias in band composition elicited through interview is likely and may take two forms.
First, some individuals will be forgotten, and these are more likely to be individuals
unrelated to other band members, since each listed member acts as a cue to remember and
list other close relatives. This means that bands elicited through recall may show higher
frequencies of close kin than would be estimated through direct observation. Thus,
numbers of coresident nonkin in table S2 represent a conservative (minimum) estimate.
Second, when informants have some doubt about presence or absence of a particular
adult on the specified day, they may decide based on an ideal model about where people
should have lived or most frequently did live. This tends to produce higher conformity
and lower variation in band composition than would actually have been observed. This
suggests that the standard errors reported in table S3 may be underestimates.
Calculations about primary kin. Custom programs written in Python allowed us to
tabulate the number of primary kin of each type (mother, father, sister, brother, daughter,
son) that were residing in all bands for each ethnographic study group. Relationships
between fathers and offspring were taken at face value as reported by informants. Half
and full siblings were combined. The average number of coresident kin for men and
women was calculated as the number of coresiding kin of each type divided by the total
number of censused adults of each sex. Mean band size experienced by individuals was
calculated as the average of all band sizes weighted by the number of individuals in that
band.
Calculation of band composition for Ache and Ju/’hoansi. Complete genealogical and
marital histories exist for adults in the Ache population and cover the precontact period of
the middle 20th century, 1950-1971 (Hill & Hurtado 1996). This allowed us to calculate
the mean number of distant kin, affines and non kin for each adult in 58 pre-contact Ache
bands. The sample was based on 20,614 dyadic relationships of 980 adults. For each band
resident, a list of all blood and affinal relatives up to a distance of 5 steps, (parent-
offspring, sibling-sibling link or a marriage), was generated and then compared to the list
of coresident adults to tabulate numbers of kin and affines. One of us (PW) hand
tabulated the same information for 6 Ju/’hoansi bands (1279 dyadic relationships of 85
adults) based on direct knowledge of the genealogies and marital relations of all persons
in each band.
Distant affinal kin in Ache bands were determined through ego’s marriage and
through the marriages of kin reported in other band censuses and inferred from the
genealogical database specifying all co-parenting in the 5-year interval centered at the
band census year. If multiple marriages were reported for the same kin member, the
inferred marriage dated nearer to the census year was given precedence.
To produce figure 2 and tables S2 and S3 primary kin and spousal relationships
were represented as dyadic links of distance of one step. Starting from each resident,
these links were extended one step at a time, generating exhaustive ego-centered lists of
consanguineal and affinal kin at increasing consecutive distances. Only the closest paths
to any alter were tabulated. Figure 2 and Table S2 disaggregates primary affines into
those genetically related to spouse (spouse’s primary kin) and those unrelated to either
ego or spouse (ego’s primary kin’s spouses) in order to estimate percent of band members
related to the nuclear family of ego. Because Ju/’hoansi data aggregated spouse’s distant
kin with other distantly related individuals (distant affines and affines of affines) we have
estimated the number of spouses distant kin by assuming that the ratio of primary to
distant kin for ego and spouse is the same.
The mean r value for all Ache coresidents in the 58 pre contact bands was
estimated using Descent software (Hagen 2005). In this calculation only consanguineal
relationships were considered. Each coresiding dyadic pair of adults was considered a
single data point; if the same pair coresided in more than one band they were counted
multiple times. The estimate takes reported paternity at face value and assumes that
individuals with no known genealogical links have a genetic coefficient of relatedness of
zero.
Confidence intervals and statistical analyses- The 95% confidence intervals for the
estimated mean number of coresident kin of each type reported in Tables 1 and S1 were
constructed by resampling with replacement from the available sample of adults in that
society. The same procedure was followed for the Figures in the Supplentary Online
Material. Sex differences in mean number of coresident kin of each type were considered
statistically significant for any society if the 95% confidence interval of the mean for
each sex did not overlap with the mean value for the opposite sex as shown in Table S1.
For the combined sample in Figure S1, the 95% confidence intervals around the mean of
the means were estimated, with a bootstrap procedure resampling the 32 society means.
The p value for testing the hypothesis of no difference between men and women in mean
number of coresident same sex siblings was obtained as follows: For each sex, the 32
mean counts of coresiding same-sex siblings were resampled and confidence intervals
were estimated for decreasing p-values (0.05, 0.02, 0.01, 0.005, 0.002, etc.), using the
bias-corrected accelerated (BCa) method (Canty & Ripley 2009; Davison & Hinkley
1997). The p value reported is the lowest for which the confidence interval for each sex
did not include the mean for the opposite sex.
There is a concern that higher mean numbers of brothers coresiding with men in
many societies might be simply due to a male biased adult sex ratio. Thus, same sex
coresidents for men would often be significantly higher than for women, giving the
appearance of common virilocal residence. However, examination of the data in table S1
shows this is not the case. There is no correlation (r = 0.028, p > 0.1) between the
population adult sex ratio reported in the 32 societies and a measure of excess
coresidence of brothers (mean number of brothers of men minus mean number of sisters
of women).
Supplementary discussion
Our sample of hunter-gatherers is global (Figure S2) and includes most of the
better-studied foraging societies of the 20th century. The bands in our study are comprised
of about 20 adults on average (range 5-64, Figure S3). However, the mean band size
experienced by an individual was 28.2 adults (weighted mean) taking into account that
more individuals live in each large band than in each small band (Table S1).
Table S1 shows the complete dataset, with mean number of coresiding kin of each
type for men and women in each society. The relative number of coresiding primary kin
living with men versus women within these bands is nicely described by a measure
developed by Helm (1965). Helm’s measure is calculated as the sum of all primary kin
living with an average man divided by the sum of all primary kin living with men and
women. Helm’s measure approaches unity for a strictly virilocal society where only men
live with kin and all women marry out, whereas it is near zero if women are philopatric
and men emigrate. A frequency distribution of Helm’s measure for the 32 hunter-
gatherers in our sample shows a slight virilocal bias (Figure S4) with a mean of 0.53
(range 0.34-0.71).
Several observations should be noted concerning values in table S1 for specific
ethnographic cases. First, statistical patterns of coresidence do not match well with
ethnographically reported post-marital residence patterns (Figure S5). Second, the highest
and lowest ratios of coresidence of male/female primary kin both come from small
samples of Australian aborigine communities that are located geographically within about
two hundred kilometers of each other. Numbers of coresiding kin for both these groups
are based on an adult sample of less than 50 individuals; thus, extreme values on the table
may be due to stochastic events and small sample size.
Figures S6 and S7 compare the Ache profiles of parental coresidence for men and
women in Ache and Ju/’hoansi. In both cases there is a steep decline in coresidence with
age. This is not due simply to parental mortality since coresidence probabilities
contingent on parental survival also show a significant age decline among the Ache
(Figure S12) and probably do for the Ju/’hoansi as well since the slope of their
coresidence decline is even steeper than that for the Ache (Figure S7).
Figures S8 and S9 compare same sex and opposite sex sibling coresidence across
the lifespan for the Ache. The trends suggest early bride service by men, followed by a
clumping of brothers and sometimes brothers-in-law into bands in middle age. Sisters
alone seem to disperse if not coresiding with brothers, and in fact Figure 2 of the main
text shows that by late middle-age sisters who survive are no more likely to coreside than
other unrelated adults. Figures S10 and S11 suggest a different age structured coresidence
pattern for the Ju/’hoansi. Bride service by men is followed by clumping of brothers and
early middle age (as among the Ache) but then a much more rapid dispersal of brothers
rather than sisters by late middle age. Thus, the Ju/’hoansi appear more sororalocal than
the Ache.
Finally Figure S12 shows the age pattern of coresidence for parents and offspring
among the Ache when parental survival is controlled. A smaller proportion of surviving
parents coreside with each adult offspring in Ache society regardless of sex. We suspect
this is because adult siblings themselves begin to disperse as they get older; thus,
surviving parents can only live with one son or daughter at a time, rather than with
groups of their adult offspring.
Comments on sample study populations and their residence patterns:
Ache- Hill and Hurtado reported in 1996 that the Ache were bilocal as far as we could
tell, and we emphasized the opportunistic nature of residence patterns and the fact that
high flexibility and associations with non-kin were typical. Recorded interviews after that
time suggest that the Ache have a cultural expectation of male kin clustering. Specifically
informants stated that men should “follow their fathers” and those who don’t are labeled
as “apa mujallangi” (those who don’t follow their fathers) or “picha mujandygi” those
who follow non kin—something considered to be an aberrant pattern. Most importantly,
interviews about clubfights in the pre-contact period clearly state that brothers and other
close male kin were the main supporters of each other in potentially lethal conflict. Ache
also frequently refer to associations and relationships that they describe as not kin based,
but based on mutual aid and assistance. There are several terms used to describe these
(“javeuatygi, rekoatygi, erupiuatygi, jujatygi”) all of which are translated into Spanish as
“amigo” = friend.
Agta- Thomas and Janet Headland have taken numerous censuses of the 600 Casiguran
Agta since 1962. The Agta live in small, widely-scattered camps in the rainforest of
eastern Luzon. Camps are small, consisting of from three to seven kin-related nuclear
households. The nuclear family is the basic kin unit. There is no social structure beyond
kinship binding together camp groups. The Agta do not have lineages or clans. A family
will rarely reside in a camp of non-related kin. The kinship system is bilateral, and the
residence norm is bilocal. In a survey in 1984, 48% of households were virilocal, 35%
uxorilocal, 8% neolocal, and 8% were ambiguous. The mean age of men at first marriage
is 21 years, and of women 18 years. Polygyny is not practiced. Life expectancy at birth is
age 23. Mean household size is 4.3 members. Most households (79%) are composed of
simple nuclear families (parents and dependent children); 17% are of augmented nuclear
families (e.g., with a cousin or grandparent present), and only 4% are composite (i.e.,
with two related couples sharing the same hearth). The outstanding feature of camp
residence patterns is that everyone living in the camp is related, either directly or serially.
An Agta camp may thus be defined as a social aggregate consisting of a core of
consanguineal kin together with affines from other aggregates. Individuals and families
are not free to move into camp groups of non-kin, except for single overnight visits. The
overriding rule requires individuals to live only with kin (Headland 1987:265-267;
Headland and Headland 2009).
Aka – Aka say and ethnographers reported (Hewlett 1991, Kitanishi 1998) that they live
uxorilocally for several years during bride service and move to a virilocal/patrilocal
residence after one or two children are born and are walking well. Bahuchet (1985)
described the Aka as multilocal and all ethnographer accounts emphasized tremendous
residential flexibility, but none of the ethnographic reports were based upon systematic
quantitative analysis. The current analysis indicates a bilocal pattern with a slight
virilocal bias, in that brothers are more likely to live together. This makes sense in that
the Aka and some ethnographic reported the expected cultural patterns while Bahuchet’s
characterization and the ethnographers’ emphasis of on-the-ground flexibility reflect the
general bilocal pattern. The bias of males living with brothers makes sense in the context
of regular cooperative net-hunting where brothers rely upon each other to go out each
day. Other studies have shown that the number of brothers a man has influences patterns
of paternal investment and residence (Hewlett 1991).
Australian groups - It is quite puzzling that the Miwuyt group of Yolngu show extremely
low levels of son-father, and brother-brother coresidence, despite being described as
generally patrilocal (Keen 1982: 626) like most other Australian groups. Likewise, the
Alywarra show higher coresidence between women and their primary kin than for men,
despite being described in the literature as patrilocal (Denham 1978 and references
therein). While we have no particular insight into this apparent contradiction, Nick
Peterson (personal communication) has suggested that sisters are more likely to coreside
in these groups because of high levels of sororal polygyny. We also note that when only
married members are listed in a census, there is a large age difference between spouses in
some of these groups which might make it less likely for listed men to be coresiding with
any primary kin because they are more likely to be dead. Because of the age pyramid
there are many more young than old individuals, and younger men are likely to be doing
bride service. Also, due to age differences between spouses, older women are almost
always widowed and may move back to live with their own close kin upon the death of a
husband. Since daughters but not sons are always married, and newly married sons (even
in their 30s) may be far away doing bride service, most older women live with their
daughters on her husband’s patrilineal territority. Peterson suggests that the most
common residence pattern of older women should be called “filialocal”.
Batak- James Eder censused all living Batak in 1980-81. These people lived in 8 different
camps located in 8 adjacent river valleys on the east coast of Palawan Island. Three of the
camps included many outsiders married in, or the children of marriages with outsiders,
and thus they were excluded from analyses. In addition, all individuals married to
outsiders in the remaining 5 camps were excluded from analysis. According to Warren
(1975), post-marital residence is customarily near the bride's parents, and this was Eder’s
general impression as well, with the caveat that over time married couples tend to move
back to the husband's natal group or to the current camp of some of his male relatives
more often than not. Nevertheless, statistical analyses shows a fairly bilocal pattern of
residence, but with higher numbers of brothers coresiding with same sex siblings than
sisters.
Hadza- Woodburn (1964) conducted many censuses for his dissertation and reported that
60% of persons who have at least one parent alive are co-resident with at least one parent.
He noted that husbands and wives both value co-residence with their mothers. Among
monogamous couples in a synchronic census he found 28 husbands and 34 wives had
mothers alive and of these 43% of husbands and 68% of wives were living with their
mothers (Woodburn 1968). There were 21 couples who had a living mother and a living
mother-in-law and 15 of these were living with the wife’s mother, 7 were living with the
husband’s mother, and 4 were not living with either mother. Nicholas Blurton Jones
found that from age 20-40 years the likelihood of a woman living with her mother was
10-20% higher than a man but at age 40 there was no difference (Jones, Hawkes, and
O'Connell 2005a). Grandmothers tend to live with whichever child stands to benefit most
from their help, for example a daughter with young nursing children. This strategy makes
perfect sense but it also makes it difficult to measure a benefit of grandmother’s co-
residence since her effect is to minimize the difference in the success of her children
(Jones, Hawkes, and O'Connell 2005b). Often camps are composed of two or three
unrelated extended families. Camps are usually referred to by the name of some senior
man, usually between 40 and 65 years of age. The core of a camp, however, tends to be a
group of sisters, one of whom the man has long been married to. Most people in camp are
related to one of these women and her parents or children. In a sample of 8 camps,
Marlowe found 32% of couples living in a camp where wife’s mother lives, 18% living
with husband’s mother, 6% living where the mothers of both reside, and 44% where
neither has a mother residing (Marlowe in press). Although there is a bias toward
uxorilocality, couples also live virilocally, bilocally, and neolocally. A couple may be
living uxorilocally one month, virilocally the next month, and neolocally a few months
later. The only appropriate term for such a pattern is multilocality (Marlowe 2004).
Hiwi- Hill and Hurtado observed that the Hiwi practiced bride service and then a strong
tendency to fratrilocal residence after the birth of a first child. Surprisingly, Arcand
(1999) labeled the Hiwi uxorilocal. We are not sure if these represents a difference
between Colombian and Venezuelan Hiwi, a change through time, or simply confusion of
bride service with long term residence.
Ju/’hoansi- We combined Marshall’s observations from the 1950s published in 1976 with
the census data in Wiessner’s 1977 Ph.D. dissertation. Wiessner notes that her camps
were more associated with Bantu cattle herders, and that Marshall’s age data is off by
about 5 years for young men (too young) and was later corrected by John Marshall and
Claire Ritchie. Ju/'hoansi parents arrange marriages for their children, preferably with
families they know and trust who reside within a 150 km radius. Wiessner found that
approximately half of Ju/’hoansi women were married before menarche and the other half
around or after menarche Wiessner (2009). Howell (2000) estimates median age at
menarche to be 16.6 years. Median age for Ju/’hoansi men at marriage is 25.5 years
(Howell 2000). Men are obliged to do bride service until the first 1-3 children are born.
The decline in coresident male siblings reflects the departure of young men to do bride
service. Of 22 males age 15-25 (20-30 with age correction) in the Marshall sample,
ten were single, six were doing bride service and living with wife's kin, and another four
were married and living with both their parents and bride's parents and so able to do bride
service without leaving their parents and sibs. The remaining two were married and living
with their own parents. One of these was married to an orphan. After bride service,
families then decide whether to reside in the husband's or wife's camp or whether to
alternate between the two.
Paliyan- Genealogies are complicated by frequent serial marriage and a 12% rate of step-
child to step-parent marriage. In general affinal relations are strong, and brother-sister
bonds are strong for life. Gardner (personal communication) agrees that bilocal is a good
label for the Paliyan residence pattern.
Comparison to previous studies and hypotheses about hunter-gatherer coresidence
patterns:
The patterns we report here modify and extend studies of hunter-gatherer social
structure based on post-marital residence rules. Our results are consistent with the
conclusion that hunter-gatherers are generally “bilocal” (Marlowe 2004) and also that a
large fraction of foraging societies are “virilocal” (Ember 1978) with female dispersal
just as among other African hominoids (Chapais 2008; Wrangham 1987). These patterns
are inconsistent with life history models that presume universal matri-kin coresidence as
the typical pattern through most of our evolutionary past (e.g., Hawkes et al. 1998: 1338),
though not necessarily inconsistent with hypothesized maternal residence strategies to
coreside with adult daughters during reproductive periods when help is most required
(Blurton Jones et al 2005; Scelza and Bleige Bird 2008). Indeed post reproductive women
may constantly weigh the fitness gains of investing in both daughters’ and sons’ offspring
along with those of helping to increase paternity certainty of sons (ie. monitoring
daughters-in-law) to make complex dynamic residence decisions.
The data also indicate that parent-offspring and sib-sib coresidential associations
are independent, something never before mentioned in anthropological or biological
literature, nor anticipated by any theoretical models of kin association. For example, one
society (Copper Eskimo) showed a significant bias toward parent-daughter association
(matrilocal/filialocal), yet brothers coresided significantly more than did sisters
(fratrilocal). Five other societies showed the same (but non-significant) tendency. When
we combine the data from all societies, we find no sex bias in parent-offspring
association, but the mean number of coresiding brothers of men (0.65) is 1.63 times the
number of coresiding sisters of women (0.40; n= 32; p<0.001; successive bootstrap BCa
method). We also note considerable variation across the societies in the tendency of
brothers to coreside. These patterns together may indicate opportunistic parental
investment in adult offspring of either sex, along with fratrilocal preference when
fraternal alliances have been critical (e.g., high in-group violence in the recent past), but
fraternal avoidance when mate competition between brothers is paramount (especially
when marital prescriptions and proscriptions are highly restrictive).
Band composition in Ache and Ju/’hoansi foragers
Because only a small fraction of adult band members are primary kin we deemed it useful
to determine the composition of remaining band members. Ache genealogies and marital
histories are quite extensive and cover the entire Northern Ache population during the
20th century (Hill and Hurtado 1996). Our computer program searched the databases for
all meiotic and marital links between individuals up to 5 steps and then assigned each
pair of individuals to the closest relationship category discovered. We were mainly
interested in all kin of pair-bonded nuclear families vs. others who were not kin.
However, we quickly realized that two types of affines are called by the same kin terms
and treated in nearly identical fashion (as far as we can tell) even though one type are
closely related to the nuclear family and the others are unrelated to either ego or spouse.
These are the primary affines that we call in-laws. Brother-in-law to ego, for example,
includes both spouse’s brother (genetically related to spouse) and sister’s husband
(unrelated to either ego or ego’s spouse). The first individual is closely genetically related
to the nuclear family members of ego, whereas the second is genetically unrelated. Thus
we decided to aggregate our membership categories in a way that allows readers to
calculate proportions of both the anthropologically typical categories (lumping all
primary in-laws), and the genetically based categories (separating spouse’s primary kin,
from primary kin’s spouses). Thus table 2 rows 1-3 include ego and ego’s kin, rows 4-6
include spouse and spouse’s kin, row 7 includes the primary affines that are ego’s
primary kin’s spouses, row 8 includes all other individuals who are linked by one
marriage and greater than 1 meiotic step out to a total of 5 steps (affines of distant kin,
and affines of affines). Finally row 9 includes all coresident adults who cannot be linked
by any of the prior criteria—we call these unrelated.
Adult coresident kin
0.0
0.2
0.4
0.6
0.8
Men's
parents
Women's
parents
Men's
sisters
Men's
brothers
Women's
sisters
Women's
brothers
Figure S1. Mean and 95% confidence intervals of number of coresiding, adult primary
kin for the combined sample of all 32 hunter-gatherer societies. Cross-sex sibling
coresidence is common, but with an overall tendency to virilocality indicated by men
coresiding with significantly more brothers than women coreside with sisters (p < 0.01,
successive bootstrap BCa method). Each society is weighted equally.
Ache
Hiwi
Aborigines
(4)
!Kung
Mbuti
Agta
Batak
Semang
Hill
Pandaram
Vedda
Chenchu
Paliyan
Inuit
(8)
North
America
(6)
Ainu
Aka
Hadza
Figure S2. World map showing the approximate location of 32 societies used in our
sample.
Mean residential band size
0 10 20 30 40 50 60
Frequency (number of societies)
0
2
4
6
8
10
12
14
Figure S3. Frequency distribution of band size (co-resident adults) for the 32 societies in
our sample.
Helm's measure
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Frequency (number of societies)
0
2
4
6
8
10
12
Figure S4. Frequency distribution of “men’s primary kin”/”total primary kin” (Helm’s
measure) for the 32 hunter-gatherer societies in our sample. This measure estimates the
fraction of all primary coresident kin in a society that are close relatives of males rather
than females. There are slightly more societies with bands that contained more primary
kin of males rather than females.
Ambilocal n=10 Matrilocal then patrilocal n=6 Patrilocal n=8
Helm's measure
0.0
0.2
0.4
0.6
0.8
1.0
Figure S5. Mean proportion of men’s primary kin/total primary kin (Helm’s measure) for
the commonly reported post-marital residence rules that have been published to describe
residence patterns in our sample of study populations. Note that there is poor
correspondence between reported residence rules and actual patterns of kin coresidence.
Parents of women
Parents of men
Age interval, years
15-21 22-29 30-44 45+
Adult coresident kin
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Parents of men
Parents of women
Figure S6. Mean number of parents coresiding with Ache men and women by age
quartile.
Figure S7. Ju/’hoansi mean number coresiding parents for men and women by age
quartile (based on data by L. Marshall).
Parents of women
Parents of men
Age interval, years
20s 30s 40s 50+
Adult coresident kin
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Parents of men
Parents of women
Age interval, years
15-21 22-29 30-44 45+
Adult coresident kin
0.0
0.2
0.4
0.6
0.8
1.0
Brothers of men
Sisters of women
Figure S8. Mean number of coresiding same sex siblings for Ache men and women by
age quartile.
Parents of women
Parents of men
Age interval, years
15-21 22-29 30-44 45+
Adult coresident kin
0.0
0.2
0.4
0.6
0.8
1.0
Sisters of men
Brothers of women
Figure S9. Mean number of coresiding opposite sex siblings for Ache men and women by
age quartile.
Age
20s 30s 40s 50+
Adult coresident kin
0.0
0.2
0.4
0.6
0.8
1.0
Brothers of men
Sisters of women
Figure S10. Mean number of coresiding same sex siblings for Ju/’hoansi men and women
by age quartile.
Parents of women
Parents of men
Age interval, years
20s 30s 40s 50+
Adult coresident kin
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Sisters of men
Brothers of women
Figure S11. Mean number of coresiding opposite sex siblings for Ju/’hoansi men and
women by age quartile.
Figure S12. Mean proportion of living parents who coreside with Ache men and women
by age quartile. Baseline indicates the proportion of adults who are unrelated by blood
or marriage (>3 genealogical steps & greater than 1 marital step removed) that
coreside. Note that parental offspring coresidence declines with age even when parental
survival is controlled.
Parents of women
Parents of men
Age interval, years
15-21 22-29 30-44 45+
Mean proportion coresiding
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Parents of men
Parents of women
Baseline
Table S1. Mean number of coresiding kin for men and women in 32 hunter-gatherer societies.
(95% confidence intervals are shown below the mean.)
Censused Total Mean exp. Adult sex Ethnographic PARENTS
MOTHERS FATHERS SISTERS
Society bands Adults band size* ratio label female male female male female male female male
Gunwinggu 1 18 18.0 0.80 patri 0.30 1.26 0.20 0.63 0.10 0.63 0.60 0.75
0-0.6 0.75-1.75 0-0.5 0.25-1 0-0.3 0.25-0.88 0.3-0.9 0.38-1
Labrador 7 86 24.1 0.62 patri 0.14 0.24 0.09 0.18 0.05 0.06 0 0.18
0.05-0.25 0.09-0.39 0.02-0.18 0.06-0.32 0-0.13 0-0.16 none 0.06-0.35
Semang 3 49 19.3 1.04 patri 0.21 0.76 0.13 0.36 0.08 0.40 0 0.44
0.04-0.38 0.48-1.04 0-0.25 0.13-0.48 0-0.21 0.17-0.61 none 0.26-0.61
Iglulik 16 216 25.5 0.98 patri 0.23 0.60 0.12 0.32 0.11 0.28 0.13 0.19
0.15-0.32 0.49-0.72 0.06-0.18 0.23-0.40 0.06-0.17 0.20-0.36 0.06-0.21 0.09-0.28
Belcher I. Inuit 4 41 11.9 0.95 ? 0.10 0.15 0.05 0.05 0.05 0.10 0.10 0.45
0-0.24 0-0.3 0-0.14 0-0.15 0-0.14 0-0.25 0-0.24 0.20-0.75
Mbuti 18 280 32.9 0.89 patri 0.21 0.57 0.12 0.32 0.09 0.25 0.27 0.37
0.14-0.28 0.46-0.68 0.07-0.18 0.24-0.39 0.04-0.14 0.17-0.33 0.18-0.36 0.27-0.49
Hiwi 3 107 36.7 0.95 matri 0.44 0.54 0.33 0.23 0.11 0.31 0.51 0.58
0.29-0.6 0.38-0.71 0.20-0.46 0.12-0.35 0.04-0.20 0.19-0.45 0.32-0.69 0.33-0.75
Angmagsalik 1 17 17.0 0.90 patri 0.20 0.75 0.10 0.50 0.10 0.25 0.20 0.25
0-0.5 0.44-1.33 0-0.33 0.13-0.88 0-0.33 0-0.63 0-0.56 0-0.63
Ainu 9 112 14.9 0.93 patri 0.24 0.15 0.12 0.11 0.12 0.04 0.34 0.57
0.14-0.36 0.06-0.26 0.05-0.21 0.04-0.20 0.05-0.21 0-0.09 0.17-0.52 0.35-0.83
Ache 58 981 20.7 1.04 matri 0.36 0.50 0.20 0.29 0.16 0.21 0.16 0.33
0.31-0.40 0.44-0.55 0.16-0.24 0.25-0.33 0.12-0.19 0.18-0.25 0.13-0.20 0.27-0.38
Paliyan 2 40 25.0 1.11 ambi 0.16 0.28 0.05 0.14 0.11 0.14 0.21 0.57
0-0.32 0.10-0.52 0-0.16 0-0.29 0-0.26 0-0.29 0.05-0.37 0.33-0.81
Nunamuit 7 215 64.9 1.03 ambi 0.38 0.37 0.18 0.18 0.20 0.19 0.52 0.79
0.29-0.51 0.28-0.49 0.12-0.25 0.09-0.22 0.11-0.25 0.10-0.24 0.30-0.64 0.51-1
Aka 9 128 16.6 0.75 patri 0.49 0.56 0.3 0.29 0.19 0.27 0.33 0.27
.36-.63 .4-.75 .21-.42 .16-.42 .10-.29 .16-.4 .19-.49 .16-.42
Chenchu 15 215 17.6 0.92 ambi 0.25 0.44 0.20 0.27 0.05 0.17 0.21 0.40
0.17-0.34 0.32-0.54 0.13-0.27 0.15-0.32 0.02-0.10 0.08-0.21 0.10-0.33 0.21-0.27
Netsilik 13 194 17.0 0.98 patri 0.32 0.39 0.19 0.23 0.13 0.16 0.06 0.19
0.22-0.44 0.27-0.5 0.12-0.28 0.15-0.31 0.07-0.20 0.08-0.23 0.02-0.11 0.10-0.28
Agta 10 117 12.8 0.95 ambi 0.27 0.35 0.15 0.19 0.12 0.16 0.27 0.37
0.15-0.4 0.21-0.49 0.07-0.25 0.11-0.30 0.05-0.20 0.07-0.26 0.15-0.38 0.23-0.54
Slavey 2 28 22.3 1.00 patri 0.46 0.50 0.33 0.29 0.13 0.21 0.53 0.29
0.2-0.73 0.21-0.79 0.13-0.53 0-0.46 0-0.33 0-0.46 0.13-0.93 0-0.54
Ojibwa 7 259 56.6 0.95 patri 0.43 0.52 0.26 0.30 0.17 0.22 0.44 0.75
0.33-0.53 0.42-0.64 0.18-0.32 0.20-0.37 0.11-0.24 0.13-0.27 0.31-0.57 0.60-0.90
Wanindiljaugwa 14 174 21.4 0.98 patri 0.33 0.07 0.33 0.07 1.46 1.54
0.22-0.41 0.02-0.13 0.24-0.42 0-0.07 1.18-1.77 1.12-1.94
Copper 4 60 16.3 1.00 ambi 0.40 0.20 0.20 0.10 0.20 0.10 0.07 0.13
0.2-0.6 0.07-0.37 0.07-0.37 0-0.20 0.07-0.37 0-0.20 0-0.17 0.03-0.27
Dogrib 3 191 81.6 0.95 patri 0.94 0.89 0.51 0.49 0.43 0.40 1.04 1.23
0.80-1.08 0.74-1.03 0.41-0.61 0.40-59 0.32-0.52 0.30-0.49 0.83-1.23 0.99-1.47
!Kung 21 297 14.5 0.90 ambi 0.62 0.71 0.37 0.40 0.26 0.30 0.31 0.50
.53-72 .59-.82 .29-.44 .33-.48 .19-.33 .23-.39 .24-.39 .38-.64
Shoshoni 18 81 7.3 0.88 ambi 0.11 0.11 0.09 0.08 0.02 0.03 0.33 0.24
0.02-0.21 0.03-0.21 0.02-0.19 0-0.18 0-0.07 0-0.08 0.19-0.47 0.08-0.42
Batak 5 145 42.6 1.27 ? 0.53 0.53 0.25 0.30 0.28 0.23 0.53 0.58
0.39-0.69 0.41-0.65 0.16-0.36 0.21-0.41 0.17-0.39 0.15-0.33 0.36-0.72 0.42-0.77
Alyawarra 4 128 39.2 0.75 patri 0.60 0.57 0.37 0.33 0.23 0.24 0.88 0.44
0.47-0.75 0.4-0.73 0.21-0.44 0.20-0.44 0.11-0.30 0.11-0.33 0.62-1.08 0.24-0.69
Vedda 2 19 11.6 1.11 matri 0.88 0.40 0.44 0.20 0.44 0.20 0.44 0.30
0.44-1.33 0.1-0.8 0.11-0.78 0-0.5 0.11-0.78 0-0.5 0.11-0.78 0.11-0.78
Paiute 9 77 11.7 0.97 ambi 0.52 0.16 0.26 0.08 0.26 0.08 0.21 0.21
0.33-0.72 0.05-0.29 0.13-0.41 0-0.18 0.13-0.41 0-0.18 0.05-0.38 0.08-0.37
Apache 16 220 18.6 1.02 matri 0.56 0.49 0.30 0.29 0.26 0.20 0.48 0.32
0.45-0.68 0.38-0.60 0.22-0.39 0.17-0.34 0.18-0.34 0.11-0.25 0.33-0.61 0.17-0.45
Takamiut 2 31 15.9 0.94 ? 0.76 0.47 0.44 0.27 0.32 0.20 0.88 0.33
0.44-1.13 0.2-0.8 0.19-0.69 0.07-0.47 0.13-0.56 0-0.40 0.44-1.38 0.07-0.67
Hadza 17 406 35.1 0.90 ambi 0.40 0.38 0.27 0.22 0.13 0.16 0.68 0.42
.26-.54 .28-.48 .16-.38 .14-.30 .05-.21 .11--.21 .47-.89 .28-.56
Hill Pandaram 19 93 5.8 1.11 matri 0.50 0.16 0.25 0.10 0.25 0.06 0.18 0.24
0.32-0.68 0.06-0.27 0.14-0.39 0.02-0.18 0.11-0.39 0-0.14 0.07-0.30 0.14-0.37
Miwuyt (Yolngu) 4 42 11.9 0.75 patri 0.30 0.06 0.17 0.06 0.13 0 0.42 0.22
0.13-0.5 0-0.17 0.04-0.33 0-0.17 0-0.25 none 0.17-0.71 0.06-0.44
* Mean experienced band size is the mean of band size weighted by the number of individuals that experience that band size.
BROTHERS DAUGHTERS SONS Total Primary Kin Helm's
Society female male female male female male female male M/(M+F) data source
Gunwinggu 0.60 2.50 0.20 0.13 0.50 0.63 2.20 5.27 0.71 Altmann 1987
0-1.6 1-3.5 0-0.4 0-0.38 0-1.2 0-1.88 1.2-3.6 3.5-7.13
Labrador 0.11 0.36 0.09 0.09 0.11 0.06 0.45 0.93 0.67 Taylor 1974
0.02-0.22 0.16-0.61 0.02-0.16 0-0.19 0.02-0.22 0-0.16 .27-.65 .64-1.27
Semang 0.46 0.72 0.13 0.08 0.38 0.40 1.18 2.40 0.67 Schebesta 1954
0.13-0.75 0.26-1 0-0.25 0-0.22 0.04-0.63 0.04-0.78 .71-1.75 1.76-3.08
Iglulik 0.18 0.56 0.12 0.11 0.31 0.28 0.97 1.74 0.64 Mathiassen 1928, Damas 1963
0.09-0.30 0.37-0.78 0.06-0.18 0.05-0.18 0.19-0.44 0.16-0.41 .78-1.17 1.47-2.03
Belcher I. Inuit 0.43 0.50 0.05 0.05 0.05 0.10 0.73 1.25 0.63 Freeman 1967
0.14-0.71 0.30-0.70 0-0.14 0-0.15 0-0.14 0-0.25 .38-1.10 .85-1.7
Mbuti 0.33 0.59 0.12 0.10 0.28 0.25 1.21 1.88 0.61 Turnbull 1965
0.24-0.44 0.47-0.72 0.07-0.18 0.05-0.16 0.18-0.41 0.14-0.36 1.02-1.43 1.64-2.12
Hiwi 0.55 1.58 0.33 0.12 0.22 0.31 2.05 3.13 0.60 Hill & Hurtado unpublished
0.29-0.78 1.16-1.90 0.15-0.53 0.04-0.22 0.07-0.36 0.06-0.61 1.62-2.51 2.63-3.63
Angmagsalik 0.20 0.25 0.10 0.13 0.4 0.25 1.10 1.63 0.60 Hansen 1914
0-0.56 0-0.50 0-0.33 0-0.38 0-0.89 0-0.63 .6-1.8 1.11-2.56
Ainu 0.53 0.89 0.12 0.13 0.10 0.04 1.33 1.78 0.57 Watanabe 1972
0.29-0.81 0.56-1.22 0.03-0.24 0.02-0.28 0.02-0.21 0-0.09 1.02-1.71 1.37-2.26
Ache 0.34 0.58 0.20 0.15 0.30 0.21 1.36 1.77 0.57 Hill & Hurtado unpublished
0.27-0.41 0.51-0.65 0.16-0.24 0.11-0.19 0.24-0.36 0.16-0.27 1.26-1.49 1.66-1.90
Paliyan 0.63 0.48 0.05 0.10 0.16 0.14 1.21 1.57 0.56 Gardner 1972, Gardner 2000
0.32-1 0.24-0.71 0-0.16 0-0.24 0-0.32 0-0.38 .74-1.68 1.14-2.05
Nunamuit 0.75 0.88 0.18 0.21 0.17 0.19 2.00 2.44 0.55 Spencer 1959, Burch 1975
0.46-0.91 0.65-1.08 0.10-0.27 0.08-0.34 0.06-0.23 0.05-0.32 1.71-2.36 2.09-2.85
Aka 0.21 0.51 0.3 0.25 0.22 0.27 1.55 1.86 0.55 Hewlett unpublished
.1-.34 .35-.69 .18-.44 .13-.4 .1-.37 .11-.47 1.25-1.86 1.53-2.25
Chenchu 0.37 0.45 0.20 0.06 0.25 0.17 1.28 1.52 0.54 von Furer-Heimendorf 1943
0.22-0.48 0.28-0.51 0.12-0.28 0.02-0.11 0.12-0.31 0.05-0.23 1.04-1.54 1.29-1.74
Netsilik 0.18 0.27 0.19 0.14 0.22 0.16 0.97 1.15 0.54 Rasmussen 1931, Damas 1969
0.09-0.30 0.19-0.35 0.12-0.29 0.07-0.22 0.12-0.34 0.07-0.25 .79-1.19 .94-1.35
Agta 0.35 0.42 0.15 0.12 0.18 0.16 1.22 1.42 0.54 Headland 1987, unpublished
0.18-0.53 0.28-0.56 0.05-0.28 0.04-0.23 0.05-0.33 0.04-0.30 .93-1.53 1.16-1.75
Slavey 0.27 1.00 0.33 0.14 0.27 0.21 1.86 2.14 0.54 Helm 1961
0-0.40 0.38-1.77 0-0.80 0-0.46 0-0.60 0-0.62 1.13-2.67 1.29-3.21
Ojibwa 0.71 0.78 0.26 0.18 0.29 0.22 2.13 2.45 0.53 Rogers 1979, Taylor 1972
0.51-0.87 0.55-0.92 0.15-0.35 0.11-0.29 0.15-0.40 0.10-0.30 1.86-2.41 2.16-2.75
Wanindiljaugwa 1.37 1.56 0.37 0.07 3.16 3.61 0.53 Rose 1960
0.79-1.52 1.15-2.07 0.24-0.72 0-0.07 2.63-3.55 2.96-4.03
Copper 0.13 0.33 0.20 0.2 0.1 0.10 0.90 0.96 0.52 Rasmussen 1932, Damas 1969
0-0.30 0.17-0.50 0.07-0.33 0.07-0.37 0-0.23 0-0.27 .6-1.27 .63-1.3
Dogrib 1.16 1.23 0.51 0.45 0.47 0.40 4.12 4.20 0.50 Helm 1965, Helm & Lurie 1961
0.88-1.44 0.97-1.49 0.31-0.73 0.27-0.67 0.29-0.68 0.22-0.59 3.62-4.61 3.71-4.69
!Kung 0.46 0.37 0.37 0.28 0.37 0.30 2.14 2.15 0.50 Marshall 1976, Weisner 1977
.33-.58 .27-.47 .27-.46 .18-.38 .27-.47 .21-.41 1.88-2.34 1.91-2.43
Shoshoni 0.21 0.37 0.09 0.03 0.07 0.03 0.81 0.78 0.49 Steward 1938
0.07-0.37 0.18-0.58 0-0.21 0-0.08 0-0.19 0-0.08 .56-1.09 .5-1.08
Batak 0.73 0.69 0.25 0.22 0.38 0.23 2.42 2.25 0.48 Eder unpublished
0.52-0.98 0.52-0.86 0.14-0.38 0.11-0.35 0.20-0.56 0.11-0.38 2.06-2.83 1.94-2.60
Alyawarra 0.33 0.65 0.37 0.31 0.25 0.24 2.43 2.21 0.48 Denham 1978
0.15-0.42 0.39-0.78 0.17-0.51 0.10-0.51 0.04-0.27 0.04-0.53 2.03-2.82 1.78-2.67
Vedda 0.33 0.60 0.44 0.40 0.22 0.20 2.31 1.90 0.45 Seligmann & Seligmann 1911
0.11-1 0.3-0.9 0.11-0.89 0-0.9 0-0.67 0-0.6 1.44-3.22 1.1-2.6
Paiute 0.21 0.32 0.26 0.26 0.08 0.08 1.28 1.03 0.45 Steward 1938
0.05-0.41 0.13-0.53 0.08-0.49 0.08-0.50 0-0.18 0-0.16 .87-1.67 .71-1.37
Apache 0.33 0.29 0.30 0.25 0.29 0.20 1.96 1.55 0.44 Goodwin 1969
0.19-0.38 0.09-0.22 0.18-0.44 0.16-0.40 0.15-0.30 0.10-0.25 1.66-2.27 1.31-1.80
Takamiut 0.31 0.67 0.44 0.33 0.25 0.27 2.64 2.07 0.44 Graburn 1969
0.06-0.63 0.27-1.07 0.06-0.94 0-0.73 0-0.56 0-0.60 1.88-3.44 1.33-2.87
Hadza 0.38 0.32 0.27 0.15 0.20 0.16 1.93 1.43 0.43 Marlowe and Wood unpublished
.28-.48 .20-.44 .15-.50 .05-.25 .11-.35 0.05-.25 1.57-2.3 1.01-1.6
Hill Pandaram 0.27 0.16 0.25 0.22 0.11 0.06 1.31 0.84 0.39 Morris 1982
0.14-0.43 0.06-0.27 0.11-0.41 0.10-0.35 0.02-0.23 0-0.14 1-1.64 .61-1.12
Miwuyt (Yolngu) 0.17 0.11 0.17 0.17 0.04 0 1.10 0.56 0.34 Shapiro 1973
0.04-0.33 0-0.28 0-0.38 0-0.50 0-0.13 none .67-1.54 .17-1
4. Supplementary Tables and Legends
Table S1 (see above). Mean number of coresiding kin of each type for men and
women in each of the 32 societies. The category “parents” is simply the sum of “mother”
and “father”. Likewise the category “total primary kin” is the sum of parents, offspring
and siblings coresiding in a band. Helm’s measure is calculated as the sum of all primary
kin residing with men, divided by the sum of all primary kin coresiding with men and
women for each society.
Ache Ju/'hoansi Estimated
Type Description
Total
dyads n/adult %
Total
dyads n/adult %
Mean
Percent^
1 Self 980 1.00 4.8 85 1.0 6.6 Own Kin
2 Primary Kin * 1540 1.57 7.5 170 2.1 13.3 24.9
3 Distant Kin 2504 2.56 12.1 70 0.8 5.5
4 Spouse 824 0.84 4.0 74 0.9 5.8 Spouse's Kin
5 Spouse's Primary Kin * 996 1.02 4.8 99 1.2 7.7 15.6
6 Spouse's Distant Kin 1158 1.18 5.6 41 0.5 3.2#
7 Primary Kin's Spouses * 970 0.99 4.7 99 1.2 7.7 Non Kin
8 Other Affines ** 6510 6.64 31.6 331 3.9 25.9# 59.5
9 No Relation 5132 5.24 24.9 310 3.6 24.2
SUM 20614 21.0 100.0 1279 15.0 100.0 100.0
Table S2. Complete band composition for 58 precontact Ache bands and 6 Ju/’hoansi
bands. Rows are defined as follows: 1) ego; 2) mother, father, brother, sister, son, and
daughter; 3) all other kin that can be linked by 5 or fewer meiotic steps such that r > 0.03;
4) spouse; 5) spouse’s primary kin; 6) spouse’s distant kin; 7) spouses of all kin of ego;
8) all combinations of kinship and marital ties up to 5 meiotic steps that include two
marital ties separating individuals; 9) individuals who are not linked in any of the seven
previous categories. (*) half sibs counted as primary kin, (**) more than 5 steps removed
from ego including 1 or 2 marriage steps, (#) estimated by assuming same ratio of
primary to distant kin for spouse as observed for ego. (^) weighting each group equally.
4. Supplementary Tables and Legends
Table S1 (see separate file). Mean number of coresiding kin of each type for men and
women in each of the 32 societies. The category “parents” is simply the sum of “mother”
and “father”. Likewise the category “total primary kin” is the sum of parents, offspring
and siblings coresiding in a band. Helm’s measure is calculated as the sum of all primary
kin residing with men, divided by the sum of all primary kin coresiding with men and
women for each society.
Ache Ju/'hoansi
Estimated
Type
Description
Total
dyads n/adult %
Total
dyads n/adult %
Mean
Percent^
1 Self 980
1.00
4.8
85
1.0
6.6
Own Kin
2 Primary Kin * 1540
1.57
7.5
170
2.1
13.3
24.9
3 Distant Kin 2504
2.56
12.1
70
0.8
5.5
4 Spouse 824
0.84
4.0
74
0.9
5.8
Spouse's Kin
5 Spouse's Primary Kin * 996
1.02
4.8
99
1.2
7.7
15.6
6 Spouse's Distant Kin 1158
1.18
5.6
41
0.5
3.2#
7 Primary Kin's Spouses * 970
0.99
4.7
99
1.2
7.7
Non Kin
8 Other Affines ** 6510
6.64
31.6
331
3.9
25.9#
59.5
9 No Relation 5132
5.24
24.9
310
3.6
24.2
SUM 20614
21.0
100.0
1279
15.0
100.0
100.0
Table S2. Complete band composition for 58 precontact Ache bands and 6 Ju/’hoansi
bands. Rows are defined as follows: 1) ego; 2) mother, father, brother, sister, son, and
daughter; 3) all other kin that can be linked by 5 or fewer meiotic steps such that r > 0.03;
4) spouse; 5) spouse’s primary kin; 6) spouse’s distant kin; 7) spouses of all kin of ego;
8) all combinations of kinship and marital ties up to 5 meiotic steps that include two
marital ties separating individuals; 9) individuals who are not linked in any of the seven
previous categories. (*) half sibs counted as primary kin, (**) more than 5 steps removed
from ego including 1 or 2 marriage steps, (#) estimated by assuming same ratio of
primary to distant kin for spouse as observed for ego. (^) weighting each group equally.
Number per adult female resident
n steps**
CI n/adult CI % CI
1
Self 481
0.00
0.00
1.00
0.00
4.7
0.0
2
Primary Kin * 653
1.11
0.01
1.36
0.07
6.4
0.3
3
Distant Kin 1186
3.51
0.03
2.47
0.14
11.6
0.7
4
Spouse 412
1.00
0.00
0.86#
0.02
4.0
0.1
5
Primary Affines 1018
2.14
0.01
2.12#
0.07
10.0
0.3
6
Distant Affines 2579
4.15
0.02
5.36
0.19
25.2
0.9
7
Affines of Affines 1352
4.25
0.02
2.81#
0.13
13.2
0.6
8
No Relation** 2543
>5
>5
5.29
0.27
24.9
1.3
SUM 10224
21.26
0.43
100.0
Number per adult male resident
N steps**
CI N/adult
CI % CI
1
Self 499
0.00
0.00
1.00
0.00
4.8
0.0
2
Primary Kin * 887
1.12
0.01
1.78^
0.07
8.5
0.4
3
Distant Kin 1318
3.47
0.03
2.64^
0.14
12.7
0.7
4
Spouse 412
1.00
0.00
0.83
0.02
4.0
0.1
5
Primary Affines 948
2.15
0.01
1.90
0.07
9.1
0.4
6
Distant Affines 2755
4.17
0.01
5.52
0.19
26.5
0.9
7
Affines of Affines 1084
4.37
0.02
2.17
0.10
10.4
0.5
8
No Relation*** 2487
>5
>5
4.98
0.24
23.9
1.2
SUM 10390
20.82
0.41
100.0
Table S3. Complete band composition from 58 precontact Ache bands, for males and
females separately. Categories as defined for table S2. The 95% confidence interval (CI)
for each measure was determined by resampling and significant differences between the
sexes are indicated. (^) males coreside with significantly more of this kin type than do
females. (#) females coreside with significantly more of this kin type than do males. (*)
half sibs counted as primary kin. (**) mean number of marital and genealogical steps to
target. (***) may include affines of some kin not coresident.
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