Older parents = more likely to have genetic defects. More likely to have a low IQ. More likely to have various mental disorders. It's all well documented.
It's no coincidence that between me and my 3 brothers, my youngest brother has the most issues. My parents were in their 40s when he was born. He's also a truecel, but he's also got a lot of issues beyond that. He has the lowest IQ out of all of us, struggled the most in school, and he's also extremely low inhib, impulsive, and can't control his anger. He has a lengthy criminal history including illegal weapons charges and assaulting a police officer. He doesn't learn from his mistakes in the past and he doesn't have any sense of future orientation. He lives only in the moment.