Infants who look like their father at birth are healthier one year later. The reason is such father–child resemblance induces a father to spend more time engaged in positive parenting. An extra day (per month) by a typical visiting father enhances child health by just over 10% of standard deviation. - https://www.sciencedirect.com/science/article/pii/S0167629616303666?via%3Dihub