Most pec (and bicep) tears that I know of are not related to "ego". I know mine wasn't. I was fully warmed up and lifting a weight I'd handled 100s of times before.
As far as "backing off", most tears come totally from nowhere. There is also a distinction of did the tendon or muscle tear. In my case, the tendon stayed on the bone but the muscle split.
Many women work out just as aggressively as men and driven by ego. There is a link out there explaining that women have larger tendon to muscle diameter, that could be the reason for fewer injuries in some cases.