It talked about how neglected children that cry all the time and do not get comfort have elevated cortisol levels that become their body’s new normal as they age, resulting in all sorts of anxiety, depression, promiscuity, etc. It changed my perspective entirely, whether it was 100% accurate or not. I don’t know what the right answer is, but if the kid is crying longer than 15 minutes, I don’t think I would use that method. But who the heck knows.