Many species of bird (and other animals) mate for life, tho. The funny part is that the three behaviours depicted are in fact part of human courtship display—human males do build houses, perform art, and gift shinny and rare stuff to attract and secure partners.








That real world logic just doesn’t apply in most fiction settings. In movies blows to the head are not dangerous at all, and they are administered lightly even to friends and family when there’s a need to take them out momentarily, with consequences not worse than a couple-pint hangover.