If someone wanted to argue that intergenerational differences are significant, they'd have to contend with the fact that the ratio of intragenerational:intergenerational variance is far smaller than intrasex:intersex or intraracial:interracial variance, and commit themselves to also being a racist or a sexist.
It's routinely taught in org-psych and related fields, for example, that different generations have X characteristic that makes them better or worse suited to a particular role. Imagine the uproar that would ensue if we taught that "women are better at teaching professions while men are better at science", or "you should prefer asian employees in STEM roles vs black employees".
Maybe someone would then say, "hey, our condemnation of racism isn't based upon some ANOVA or arbitrary significance test- we aren't racist because Every Human has intrinsic worth." In which case, we can stop promulgating this antiscientific ingroup/outgroup hysteria and just focus on the Every Human part.