From the article there are actually a number of weak correlates: a man with smaller testes, for example. But it concludes with the prefrontal cortex being the l

From the article there are actually a number of weak correlates: a man with smaller testes, for example. But it concludes with the prefrontal cortex being the largest discriminator, all other factors considered. It would seem that picking a partner who is capable and willing to use rational thought to override emotional responses would be a successful strategy - more capable of dealing with the frustrating reality of childcare, less likely to leave in search of another mate.