It’s a hard thing to predict for me, cause I don’t know enough about it, but here are my thoughts:
Even with sexual selection being the biggest factor in our evolution, our DNA isn’t necessarily the deciding factor. Not only is there the entire cosmetic side to take into account; the fact that you can make yourself look a lot more sexually attractive than you would otherwise be to the average person of the opposite sex, but you also have your upbringing, your social environment and image, your personality, and a great many other factors that decide who you’re generally going to be attracted to and who will be attracted to you.
And even if it was just about looks, in a human society it’s obviously not just the most attractive people that are having sex and procreating, which automatically means that sexual selection wouldn’t be very straight forward for us. Being sexually attractive doesn’t equal having more offspring here.
I don’t agree with that, no, I think your friend is talking nonsense.
People who are suicidal are so because of their own reasons. It’s extremely difficult to say that given their conditions (from genetic predispositions to upbringing to external circumstances) others wouldn’t be suicidal as well, and it’s extremely easy to judge from the sidelines when your own situation or mental condition is fine.
Now, just to humor your friend, let’s say that he’s correct and that every person who has ever been suicidal was simply weak. No other psychological or external factors to take into account, they’re all just wimps. Then even in that case, it’s a very wrong mentality to look down on or mock these people. What good would that do?
How is it productive, right or rational? Considering someone a loser or an idiot does not change anything about them, it doesn’t make the world a better place, it just makes you more judgmental. ;)