A tainted work ethic
The quoted research found that men get their work ethic (or lack thereof) from their fathers. It’s often the father, more than the mother, who pushes sons to strive to work harder and put in the work even when they no longer feel like it. Without a father around to do that, a man might not be very self-driven later in life. If a boy grows up with a father who doesn’t have much work ethic, he may also follow his lead, since boys look to fathers as role models. On the reverse end of the spectrum, some boys grow up with militant fathers who push them to work too hard and enforce an all-work-no-play mentality, which can also be carried into adulthood.