It's Mother's Day today in the U.S. on the planet Earth. In honor of the occasion, I've been using the hand-decorated mug my son made for me (even though the marker ink came off on my hand) and thinking about alien parents. According to the "Your Inner Monkey" episode of the documentary Your Inner Fish (more influence from my son, as he was briefly obsessed with this series), humans are born with brains that are relatively undeveloped compared to monkeys. This is a feature, not a bug, since that means we have an extended childhood that allows our brains to develop over a couple of decades, giving us time to be socialized and educated.That means human children need more intensive nurturing than other animals that mature more quickly. A lot of this nurturing comes from the child's mother, though fathers, other relatives, teachers, and other adults can influence a child as well.
Do you think sentient life forms on other planets require this much nurturing as they develop? If so, do you think it comes from their mother, or whatever the equivalent is? Other life forms may have more than two parents, or may be raised by other members of their race besides their biological parents. No matter what customs apply, I expect natural selection would still favor parents who bond with their offspring--and offspring who form an attachment to their parents would get more support as they mature.
Here's a video featuring one of my favorite alien mothers, the Horta from the original Star Trek series:
You have to feel sorry for a mother who has to care for an entire planet's worth of offspring by herself.
And if I may insert a shameless plug, you can read about a human mother in my SF Catalyst Chronicles series.