I think further investigation would reveal that is at most a Western cultural thing, not a hardwired human universal. Elsewhere in time and place, 4 has been the important number—e.g. recurrences of 4 and 40 in the Hebrew scriptures; the importance of 4 and (negatively) 8 in Chinese culture, etc.. Possibly some other digits have performed similarly in other places as well.
I think further investigation would reveal that is at most a Western cultural thing, not a hardwired human universal. Elsewhere in time and place, 4 has been the important number—e.g. recurrences of 4 and 40 in the Hebrew scriptures; the importance of 4 and (negatively) 8 in Chinese culture, etc.. Possibly some other digits have performed similarly in other places as well.