Differences in Hadza Adult Height Based on Schooling

This report investigates the impact of schooling on the height of Hadza adults, a hunter-gatherer community in Tanzania. The study analyzes data collected on height and schooling, comparing individuals over 20 years old. The research explores whether there are significant height differences between schooled and non-schooled groups, considering factors like diet, nutritional aspects, and physical activities. The findings indicate no significant difference in height among Hadza male adults. However, the study reveals evidence that schooling is associated with an increase in height among Hadza female adults. The report also discusses the Hadza people's reliance on hunting and gathering for sustenance and the influence of seasonal food availability on their diet. The study aims to provide insights into the relationship between energy, exercise, and height within the Hadza community, considering the impact of schooling on the growth and development of children.

Differences in the height of Hadza adults
who attended school as a child and those
who did not
By
Module Convenor
Date:04/05/2018

ACKNOWLEDGEMENT
Firstly, I would give thanks to God for blessing me with the motivation to complete the
project with success. Then I would like to special thanks in particular to my supervisor and also
to as well as, who provided their valuable guidance and helped me to patch this project. Their
suggestions and instructions have served as major contribution in order to complete the project.
I am so thankful to all those people who have given me provision, guidance as well as
much needed motivation so as to complete the current research study. This includes support from
my team members, family and friends who helped me in all possible accords. This led to
successful completion of dissertation and achievement of relevant results. With all the support
given by these people who have immensely helped in developing my understanding and
knowledge of the topic selected in the dissertation.
ABSTRACT

In thehunter-gatherer society most of the foods is obtained through wild plants and from
wild animals. The Hadza is one such hunter gatherer society, whose diet includes grasses, tubers,
fruits, seeds and nuts. Due to the lack of having skills in relation to killing larger animals,
Hadzatypically procure meat from smaller to larger game. This study investigated whether height
of Hadza adultswho attended school as a child varies from those who did not. The primary data
pertaining to height and schooling were gathered by other researchersover several years. From
this, individuals aged over 20 were selected and – for both males and females – height compared
between schooled and non-schooled groups. In the case of Hadzamale adults,no
significantdifference was found. However, in the context of female adults, there was evidence
that schooling was associated with an increase in height.
Key Words;
Hunter-gatherers, mate choices, body size or height, mortality, demography.

TABLE OF CONTENTS
CHAPTER 1: INTRODUCTION....................................................................................................1
Overview of Hadza height...........................................................................................................1
Aim and objectives......................................................................................................................2
Significance of the study.............................................................................................................3
CHAPTER 2: RESEARCH METHODOLOGY.............................................................................5
CHAPTER 3: DATA ANALYSIS AND FINDINGS.....................................................................7
CHAPTER 5: DISCUSSION........................................................................................................12
Limitations.................................................................................................................................18
Possible research areas..............................................................................................................18
CONCLUSION..............................................................................................................................19
REFERENCES..............................................................................................................................20

CHAPTER 1: INTRODUCTION
Overview of Hadza height
The Hadza are an indigenous group who live in north-central Tanzania near LakeEyasi.
They are believed to be one of the oldest tribe remains in the region. Approximately, all Hadza
people highly rely on gathering and hunting for the majority of their diet (Sassaman, 2004). Hadza
males comeunder the category of leanest Africans. Due to the larger muscle massHadza males
are above the average in weight for height.In the study, author presented that due to the
inequality of sexes in feeding during growth stage differences take place in the height aspect
(Hiernaux and Hartono, 1980). From assessment, it has found that height is one of the main
factors which closely influencehuman mate preferences and choices. In western societies,
women prefer to marry with themen who are taller in comparison to themselves
(Sorokowskiet.al., 2017). However,in the context of non-western societies such as
Hadzadifferences in the size or appearance between the sexes of individuals take
place(Sorokowskiet.al., 2017). InHadza,preferences for sexual dimorphism in stature and actual
SDS (sexual dimorphism stature) are highly correlated in the context of both men and
women.Hence, height differences with the partners among Hadzatake place on the basis of their
preferences. Further, in the Hadza, population mating is random in relation to the size or height
aspects (Sear and Marlowe, 2009). It presents that matting preferences among hadza are not
influenced as per height.This study also indicated that at the time of choosing a mate,size and
strength are not considered by Hadza people.Heightusually indicates health, productivity and
overall quality.However,among Hadzapeople matting patternlackssize aspects as well as not
identical across all the population.
This study will assess whether attending school has an impact on height of adults among
the Hadza.There are several factors which in turn have significant impact on the height of
individuals such as diet, nutritional aspects and physical activities etc (Urlacher and Kramer,
2018). Moreover nutritional aspects have some influence on health and thereby affect growth of
children. Hunter-gatherer describes a society, where most or all of the foods is obtained from
wild plants or hunting wild animals.By contrast, agricultural societies are highly reliant on
domesticated species (Samson and et.al., 2017). Hence, hunting and gathering people depend
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primarily on wild food for subsistence. Strategies of hunter gatherers are highly influenced by
local environment. Hadzadiet include grasses, tubers, fruits, seeds and nuts. Hence, diet of hunter
gatherers can say to be good as it includes enough protein, fat as well as other healthy
elements(Berbesque, 2009). However, availability of food from plants and others arehighly
affected by seasonal aspects.Children who go to school are provided with several nutritional
sefoodsthat contribute to their growth and development. In contrast to this, children who do not
go to the school havelimited diet plan or food options (Jones and Marlowe, 2002). Further,
through investigation, it has been assessed that, as per Marlowe (2002), enthusiasm level of them
for eating is highly matched by an abundance of ingredients around them. Hence, tracking and
foraging skills are needed to find them. Along with this, it has identified from the evaluation that
hunter gatherers shares everything as theirs is an egalitarian society.
Past studies conducted on several countries show that the relationship between height and
quality of diet is significant and positive considering several factors such as nutritional aspects,
lifestyle etc. It has been revealed that the Hadza diet contains great source of fibre, potassium as
well as water but it is seasonally lean in lipids; this in turnplaces has a negative impact on the
growth of children (Senghor and et.al., 2018). Protein,carbohydrates and fatsare the main
elements that contribute in the growth of children.Moreover, carbohydrate and fats provide
children with energy for growing and physical activities. In addition to this, protein builds,
maintains and repair body tissue so that it is considered as vital element for children growth. Diet
products which are undertaken by Hadza peoplecontainthequantity of fat and proteins. Further,
honey is highly used by Hadza people, and this contains low protein and fat, 400 Kcal / 100g
(Murray and et.al., 2001). In addition to this, drupes and berries are low in fat as well protein.
Thus, considering all aspects it can be presented that Hadza people or children diet plan has
significant impact on their growth.
Aim and objectives
The aim of this study is toanalyse whetherthe height of adults who attended school as a
child differs from that of adults that did not attend school as a child.
H0 (Null hypothesis): There will be no difference in height between adult Hadza that attended
school as children and those that did not attend school.
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H1(Alternative hypothesis): Adult Hadza that attended school as children will be taller than
those that didn’t attend school.
Significance of the study
The present study and its outcomes are important as they will provide insight into the
extent to which energy as well as exercisehas an impact on height of Hadza adults. In the past
studies (Hiernaux& Hartono, 1980; Marlowe and Sear, 2009), focus was not placed on the aspects
such as energy and exercise which have significant impact on both health as well as height of the
individuals. However, Hadza people are considered as highly active as they strongly engaged in
physical activities. Further, it has been assessed that physical activities and exercise have
positive impact on the health of individuals (Dobbins and et.al., 2017). This report will test
whether height of Hadzaadults differ from who attended schools as a child or not. By doing
analysis of previous studies, it has assessed that societies with high caloric budget usually enjoy
earlier growth cessation, faster body growth and increasing size level (Migliano, Vinicius and
Lahr, 2007).
Besides this, studies which were published earlier clearly showthe manner in which
height has an impact on the matting choicesor pattern in a population of Baka Pygmies (Stulp
and et.al., 2015).Further, a study which was published earlier presents that, several factors
impact height of individuals include environmental conditions, temperature, nutritional aspects,
living standard etc (Silberbauer, 1981).All such findings present thatearlier no specific study was
carried out by other scholars on the schooling background of Hadza people and its influence on
height. Past studies present that Hadza men consumed large amount of kilocalories while
foraging. Further, it has found from the investigation that Hadza men eat more while out of the
camp. Such men laid lower level of emphasis on consuming food which they brought back
(Murray and et.al., 2001). A previousreport clearly shows that men usually feed themselves
when foraging out of camp (Pfeiffer, 2015). Further, author stated in their study that preference
of Hadza men and women differs significantly in terms of food. Men give high level of
importance to meat and honey.
Along with this, prior studies entailed that significant difference take place in the mate
choices in the context of Hadzacommunity and western society.In other words, in western
society, taller men marry with long heighted women.Unlike western society, size or heightlevel
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does not matter for Hadzapeople in relation to mate choices (Sear and Marlowe, 2009).
Considering an overall evaluation, it can be depicted that in past discussions were made by
theresearchers on the topics like mate choices, food preferences and eating behaviour or
pattern.Thus, all such aspects clearly shows that no significant studies were doneearlier to
determine the impact of schooling years or background on the height of Hadzamale
adults.Hence, by taking into account such gap study has been conducted to ascertain
whetheradultheight is differentfor Hadzawho attended school as children or not.In addition to
this, there was no significant studies are available in relation to such topic.Sear and Marlowe
(2009), Hiernaux and Hartono (1980), Sorokowski and et.al.,(2015), Sherry and Marlowe (2007)
did not consider schooling aspect in the evaluation.Thus, my study will give significant input to
other scholars in this area of research pertaining to extent to which school attendance has an
impact on height (Wadley, Tamaryn and Michael 2009).
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CHAPTER 2: RESEARCH METHODOLOGY
The Hadza community is thought to contain approximately 1000-1500 individuals and
lives in a mobile compass.Each camp comprises around 30 people an average. Hadza men
usually forage individually, and during the day they usually feed themselves while foraging, and
also bring home some honey, fruit, or wild game when available. Women forage in larger
parties, and usually bring home berries, baobab fruit and tubers, depending on availability.
Sometime both men and women also forage cooperatively for honey and fruit, and at least one
adult male will usually accompany a group of foraging women (Berbesque and et.al., 2016).
During the wet season, the diet is composed mostly of honey, some fruit, tubers, and occasional
meat (Marlowe and et.al., 2014).
However,Hadza sexual dimorphism (SDS) did not show any preference andsignificant
correlations to actual partner SDS(Sorokowski and et.al., 2015). Although there is a positive
assortative has been reported for height in a westernsocieties, bywhichindividuals tend to prefer
taller partner, for instance if a female is taller so the preference would be a taller male. In
addition, by (Marlow, 2010; Sear and Marlowe,2009) have also added, that both male and female
typically marry at very young age, females marry at the age of 17-18, whereas male at around 20.
From assessment, it has also identified that female choice to the main factor of leading the
marriage so male willing to marry a wide range of female. So therefore, polyandrous marriage
does not exist amongst them and around 4% of men have two views (Starkweather, 2010).
Yet on the other hand for the study, all the participantheight was measured by using
anthropometer. The participant did not know their exact age, and was self-reported as an
estimated by authors(Sorokowski and et.al.,2015)
PROCEDURE
Research type:Qualitative andquantitative are the main two research types which
researcher can select for the study. In the field of research, qualitative study is suitable where
emphasis is placed on gaining deeper insight about underlying reasons, opinions and
motivations. Hence, for analysingpotential differences in the height of Hadzaadults who attended
school as a child and those who did not quantitative research has been selected.
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Sampling and data collection: For assessing the factors that impact growth of Hadza
children data been gathered by the researcher from secondarysources. Population in the context
of present study includes individuals who had attended camps. For data collection, 25 camps
were visited by the researcher. Inthis, opportunistic sampling technique respondents have been
selected for the presented study.Data was gathered by Dr Colette Berbesqueand other researchers
over a decade.Further, several books, journals and scholarly articles related toevolutionary
perspectives on human rights variation, pygmies, Hunter-gatherers,etc.have been evaluated.
Thisin turn helps in supporting primary data findings and evaluation in a structured way.
Data analysis:With the motive to find out the impact of schooling on adult’s height, data
has been gathered from the year of 2001 through several camps. For testing my hypothesis,
descriptive statistics and independent sampleT test has been applied. Normality test helps in
assessing whether parametric test can be used for testing concerned hypothesis or not.Moreover,
descriptive statistics help in assessing the average heightpertaining to the adults who attend
school and those who don’t. Hence, in this, emphasis has been placed on analysing the impact of
schooling years on the height of individuals whoseage is above 20.By evaluating the data set
pertaining to theindividuals aged over 20, the hypothesis has been tested. The rationale behind
undertaking independent sample t test is that it helps in assessing differences in the mean value
of two independent groups. In this, height is considered as dependent variable and school
attendance or not as the independent variable.
Ethical considerations:In the present study, research has complied with all the necessary
ethical aspects. In the gathered data set, for avoiding the level of biasnessno modifications were
done in the data set. In addition to this, confidentiality has been maintained regarding the
gathered data set. Data regarding the height, age, weight, schooling years will not be disclosed to
others.
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CHAPTER 3: DATA ANALYSIS AND FINDINGS
The main motive behind conducting the present study is to ascertain whether height of
Hadzaadults differ between those who attended school as a child and those that did not.
Results
Table 1: Descriptive statistics of Males (adults aged over 20)
age height weight schooling years
Mean 41.7037 161.2593 52.38333 1.888889
Standard Error 1.933129 1.07827 0.940426 0.378185
Median 37 161.15 52.2 0
Mode 36 171 47.2 0
Standard Deviation 14.20554 7.923634 6.91069 2.779077
Sample Variance 201.7973 62.78397 47.75764 7.72327
Range 51 32.6 31.8 9
Minimum 21 145.4 40 0
Maximum 72 178 71.8 9
Count 54 54 54 54
Interpretation:The descriptive statistics (Table 1) show that average height of all males,
aged over 20, was 161.26 cm. In addition to this, minimum and maximum height are 145.4 &
178 respectively.
Table 2: Descriptivestatistics of height on the basis of schooling level
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height of non-school attending
males
height of school attending
males
Mean 159.7677 163.2696
Standard Error 1.509799 1.437574
Median 158.3 162.8
Standard
Deviation 8.406204 6.894361
Sample Variance 70.66426 47.53221
Kurtosis -0.50353 -0.79599
Skewness 0.356687 -0.24152
Range 32.6 23.3
Minimum 145.4 150.8
Maximum 178 174.1
Sum 4952.8 3755.2
Count 31 23
Interpretation:Average height of non-school attending males, aged over 20, was
159.77cm. Average height level of school goer adults were 163.27cm (Table 2)
Table 3: Independent sample t test (Hadza male adults)
T-Test
Group Statistics
yrs_schooling N Mean Std. Deviation Std. Error Mean
height >= 1.00 23 163.2696 6.89436 1.43757
< 1.00 31 159.7677 8.40620 1.50980
Independent Samples Test
Levene's Test for
Equality of
Variances
t-test for Equality of Means
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