[ridgeguy]

From another article about this research [1], here's what they controlled for in terms of other potential correlations:

"This effect persisted after controlling for parent's social/economic status, qualifications and employment."

[1] https://www.eurekalert.org/pub_releases/2017-06/kcl-odh06191...

Haven't read the original paper yet, so no opinion on quality of the reported research.

[zamalek]

Interesting. That might lead to questions about genetic expression in semen, but then you'd expect daughters to not be immune.