Dead men tell no tales:
How the Homo sapiens became Homo
Roman Zakharenko, NRU Higher School of Economics, Russia
The paper explains long-term changes in birth, death rates and
attitude to personal consumption by changing patterns of
cultural transmission. When communities are culturally
isolated, they are focused on population growth, resulting in
large fertility and welfare transfers to children, limited adult
consumption and lack of old-age support. With increasing
cultural contact across communities, successful cultural traits
induce their hosts to attempt becoming celebrities by limiting
fertility and increasing longevity via higher consumption and
old-age arrangements. Empirical analysis confirms that
celebrities have fewer children and live longer; their presence
precedes reduced aggregate birth and death rates.
The Homo sapiens
Theoretical biology: survival requires maximization of
population growth rate.
Lifecycle implications for humans: adults should have many
children, support them during childhood...
own consumption of adults should be modest, just enough to
support of elderly is not optimal.
Good description of a Malthusian human, not relevant for
The Homo economicus
Theoretical economics: humans maximize material wealth.
Consumption-centered objective explains many aspects of
modern behavior: demand for luxurious lifestyles, old-age
benefits. Becker explains declining fertility.
There are evolutionary theories of demographic transition (e.g.
Galor and Moav (2002)), but concern for consumption is
This paper explains the changing lifecycle of humans (fertility,
consumption choices, old-age support) by changing patterns of
Compared to other species, humans have unprecedented
ability to copy each others behavior (Boyd and Richerson,
1985), which leads to rise of cultures.
Initially CT was mostly vertical due to low literacy, high
transportation cost, low urbanization.
As these factors change, CT becomes increasingly oblique,
which is the main driving force of cultural change in the model.
Narrative of this paper
Under vertical CT, evolution of culture parallels that of genes,
leading to selection of Homo sapiens cultures that maximize
population growth rate.
Under oblique CT, alternative cultures may help attract more
A key assumption in the model is that a role model may draw
CT.within community and more such influence
outside.CT causes more investment into longevity at
Feldman (2004) and Zakharenko (2016): lower
No strong theory of how preferences for luxurious lifestyle
and for old-age support evolve.
La Ferrara et al. (2012): fertility in Brazilian communities is
reduced by movies portraying successful low-fertility families.
Van Bavel (2004): 19-th century Flemish couples in Leuven
reduced their fertility if their neighbors were Frenchspeaking.
Amish community: maintain isolation from external cultural
role models, and preserve high fertility at the same time.
Model based on Robson and Kaplan (2003). Continuous
Many communities of humans, each having unique culture.
Single consumption good, energy.
Age 0 to a1: children, can only consume. Form cultural identity at
age a1 by picking up a role model among living adults or elderly.
Age a1 to a2: adults, can produce: (i) the consumption good, with
exogenous age-dependent productivity y(a) > 0, (ii) newborn
children, (iii) also pose as role models for those who form their
Age a2 to a3: old age. Can only pose as role models.
Mortality, fertility, objective
At any age, mortality is a Poisson process with rate (c)c).
Birth of new human requires investment of C0 units of energy.
Objective is max growth rate r of community population.
When CT is only vertical, steady state is Malthusian; no old-age
Oblique cultural transmission
With probability q, a follower of age a1 picks up a role model
outside own community.
Any living individual above age a1 can become a role model.
Followers who picked up external cultural types migrate to
community of role model.
Any role model will draw followers at endogenous Poisson rate,
same for all.
Theorem 1 dead men tell no tales: consumption rises, and
therefore mortality falls, with cultural openness q at every age
Theorem 2: the birth rate falls as cultural openness q rises.
When q rises, some communities may adapt to new environment
sooner than others.
Which means they will attract many cultural followers, making
test whether celebrities have lower fertility and mortality,
more energy on themselves.
birth and death
I.e. their lifestyle is more consistent with Homo economicus.
As culture of celebrities spreads, aggregate population birth and
Celebrity data: Pantheon 1.0 dataset. Lists all individuals whose
death rates decline.
Wikipedia pages were translated into 25+ languages as of 2013.
11341 observations total.
Also perform web scraping for additional biographical info.
Data on general population: national censuses, CPS, PSID, Human
Fertility project, Human Mortality project, etc.
Celebrities are different
Fertility subsample: we manually collected fertility data for all
celebrity women born in 1750-1970, who lived 45+ years. 760
239 celebrity women (31.4%) had no children at all.
Mean difference between celebrity fertility and that of average
woman of same country, cohort: -1.15(0.07).
If education is controlled for, difference is -0.53(0.08).
Differences are robust across geographic regions, educational
Mortality study: test whether celebrity status affects 6-year survival
Control for age, age squared, gender, education, time trend.
Conclusion: celebrities have significantly lower mortality.
Celebrities are influential
I construct a measure of country-level time-varying celebrity
influence, roughly equal to # of celebrities per capita.
Hypothesis: celebrity influence Granger-causes lower aggregate
birth, death rates.
Controls: aggregate educational levels, income, time trend.
Effect is negative and significant before 1950, much weaker
The paper highlights
Further empirical study requires better data on the patterns of
such cultural influence.
Roman Zakharenko, Associate Professor, International College of Econ and Finance at NRU Higher School of Economics. [email protected], http://www.rzak.ru.
Mobile Data Protection. Mobile data protection (MDP) is a category of products for securing data on movable storage systems - laptops, smartphones, and removable media. Provides common protection policies across multiple platforms. Provides auditable proof that data is protected. Should...
Literary Style. Plain Style. References to Bible. Reflected character and scope of the reading public. Some elaborate imagery, prose, complex metaphor…but meaning is always clear. Types. Poetry. Sermon. Journal
What are Critical lens? Literary theories were developed as a means to understand the various ways people read texts. The proponents of each theory believe their theory is the theory, but most of us interpret texts according to the "rules"...
Presentation contains 34 Slides in total. Premium Members can download Full . Versions of All the Powerpoint . Presentations. Premium Membership is for Lifetime. All Presentations are 100% . editable . with . exceptional design . and . content which...
One drug might save her: a form of radium that a druggist in the same town had recently discovered. The druggist was charging $2,000, ten times what the drug cost him to make. The sick woman's husband, Heinz, went to...
Tudor Portsmouth. The Square Tower is among the earliest stone fortifications built in what is now known as Old Portsmouth. The tower was built in 1494 during the reign of Henry VII and was the residence of the military governor.