I don't remember the source but when I google it looks like I am wrong. I still find the family unit very interesting...

"A recent study from Jagiellonian University shows that fathers with daughters tend to live longer lives, with each daughter adding approximately 74 weeks to their lifespan. In contrast, both daughters and sons negatively impact a mother`s health and reduce her lifespan, according to the study. However, other research suggests parenthood, regardless of gender, can extend both parents` lifespans."