https://pubmed.ncbi.nlm.nih.gov/25131282/

so iq is dropping because unlike the cope of ''muh women choose dumb jocks or thugs'' it is actually inteeligent women, not intelligent men who are less likely to reproduce, it is probably because of men's ''muh submissive obedient housewife'' delusion coming from 50's advertisement that is making them choose dysgeny.