I think he's overstating how much effect T has on this.

I'm on HRT due to past medical issues that drastically reduced my T levels. I remember what it was like to have my T really low, Now that I'm on T, and probably about normal or higher than average for my age, I can't say its changed drastically my attitude towards my children, how gentle I am towards them and much less increased my willingness or proclivity to leave my family or my wife and seek another partner. If anything its made me more protective and I've had more a sense of duty towards my family, to protect them and be the first line of defense against whatever threats minor and major exist. The worst of it has been a shortness of temper but I keep it in check, its basically like being 20 again and being older and wiser, I can channel it into positive action.

I wonder if he studied fathers who are physically active and do things like weight lifting or MMA, that naturally elevate T levels would agree that the line drawn between animals with higher T and humans are being overly correlated.

I think it true that modern childrearing might have an affect on activity levels, but small changes in T level produce very outsized effects. If anything literature understates the role that hormones play in human cognition.