Economic Stress and the Secondary Sex Ratio: Ireland, Iceland, Greece and Latvia

Introduction: Male live births occur slightly in excess of female live births at a ratio of approximately 0.515 (male/total births). Stress has been shown to reduce M/F, including stress engendered by contracting economies. This study was carried out in order to ascertain whether the economic depression caused by the Eurozone recession at the end of the previous decade influenced M/F in the European countries most heavily affected, namely Iceland, Ireland, Greece and Latvia.
Methods: Annual data on male and female live births were obtained directly from the World Health Organisation except for Latvia which was obtained from Eurostat. Quarterly data for Ireland was obtained from the Irish Central Statistics Office.
Results: There were no significant changes in M/F except in Ireland which showed a sharp and highly significant dip in 2007 due to a fall in M/F in the last quarter only (p<0.0001).
Discussion: Darwinian evolution should encourage species to adapt to changing circumstances by altering the odds of having a child of a specific gender. Parents without stress and in good condition should produce sons since these are theoretically capable of producing more offspring, and vice-versa. The findings for Ireland support the contention that economic stress is also capable of depressing M/F.