The paper finds evidence that having daughters makes people more sympathetic to left-wing parties. Acquiring sons, by contrast, makes individuals more right-wing. Ceteris paribus, in our panel data, every extra daughter (or son) leads a person to be approximately 2 percentage points more likely to vote Left (or Right). Our data come principally from Great Britain, but we show that the basic result can be replicated on German micro data.In a Telegraph article, the study's authors argue that parents, especially fathers, adopt sympathies for women's issues and social equality:
A long-standing idea in western society is that parents influence the behavior and psychology of their children. Following previous research, the analysis suggests the reverse idea, namely, that children shape their parents.
Professor Oswald said that having daughters made men "gradually shift their political stance and become more sympathetic to the 'female' desire for a ... larger amount for the public good".
"They become more Left-wing. Similarly, a mother with sons becomes sympathetic to the 'male' case for lower taxes and a smaller supply of public goods," he said.
But one scientist believes this is overly simplistic, perpetuating gender stereotypes, and offers his own biological interpretation:
However Arthur Mayne, a biologist with three sons, dismissed the approach as "simplistic" and said the idea that women were "more likely to be softer politically than men" could be seen as a stereotype.
"Recent studies seem to prove that women with higher levels of testosterone – who are more likely to display dominant, positive behaviours – seem to produce more sons than daughters," he said.
"Women with lower levels of testosterone, who are more likely to be empathetic and better listeners, tend to produce more daughters.
"It could be that the women who are most likely to produce daughters pick a partner who is closer to her more empathetic attitude to life.
"Hence people who are already more liberal may produce more daughters and those who are already conservative may produce more sons."
Andrew Gelman, guest posting at FiveThirtyEight, offers his thoughts on this study.
Discuss amongst yourselves.