Secondary sex ratio variation during stressful times

The impact of the French Revolutionary Wars on a German parish (1787–1802)

Bibliographic Data

ID17701626
AuthorsAriane Kemkes (corresponding author)
Year2006
Volume18
Issue6
Pages806-821
Publication date2006-01-01
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueAmerican Journal of Human Biology (JOURNAL)
Journal identifiersISSN: 1042-0533 • E-ISSN: 1520-6300
PublisherWiley (PUBLISHER • GB)
DOI10.1002/ajhb.20562
PMID17039472
OpenAlexW2012570603
LanguageEN
Citations received17
References cited91

The observation that declines in the human secondary sex ratio (SSR) may be linked to stressful periconceptional periods has received considerable attention (Catalano [2003] Hum Reprod 18:1972-1975; Catalano et al. [2005] Int J Epidemiol 34:944-948, [2005] Hum Reprod 20:1221-1227, [2005] Paediatr Perinat Epidemiol 19:413-420). For the purpose of testing the external validity of this phenomenon, birth records from four German village genealogies (N = 1,048) were analyzed to study the impact of the French Revolutionary Wars (1787-1802) on the proportion of male births. All births were subdivided into three cohorts (prewar, 1787-1792; war, 1792-1797; and postwar, 1797-1802). Differences in SSR between cohorts achieved statistical significance (chi2= 7.695; df = 2; P = 0.021). In addition, changes in SSR before, during, and after the wars were monitored by risk analysis. Using the SSR of the prewar period as a control, the results of the war cohort failed to achieve statistical significance (regression coefficient, -0.257; ExpB= 0.773; P = 0.118), while the odds reduction of 32.3% in the postwar period proved to be statistically significant (regression coefficient, -0.390; ExpB= 0.677; P = 0.006). It is hypothesized that the experience of postwar economic hardship (attributable to lowered food availability paired with dietary changes) represents the most likely proximate cause. The study also finds evidence of a parental sex ratio manipulation strategy meant to offset the female-biased SSR after the wars. It is argued that from an evolutionary perspective both the decline in SSR in response to stress as well as parental manipulation of the tertiary sex ratio convey reproductive advantages

Cohort · German · Hum · Logistic regression · Odds · Odds ratio · Sociology · Statistical significance · Birth, Development, and Health · Demographic Trends and Gender Preferences · Demography · Global Maternal and Child Health · History · Medicine · Internal Medicine