This is an extremely common practice in animation where, to establish a familial relationship, a child looks more or less identical to one of their parents. This frequently occurs when a show uses garish or outlandish designs, where subtlety and fine physical detail are already lost, and we need a quick visual aid that other characters may not seem to notice.
If a family is the stereotypical four-member "nuclear" one, the children will usually resemble the respective same-sex parents.
In an attempt to mix things up, however, there may be a family in which the children resemble the respective opposite-sex parents instead. Another common variant is to have the children look nearly identical to the respective same-sex parents, but with the hair or eye colors of the opposite-sex ones.
If there is a Tomboy and Girly Girl or a Sensitive Guy and Manly Man, the tomboy and the manly man will usually resemble the father, while the girly girl and the sensitive guy will look like the mother.
Apart from its usage in character design, this trope can also play a role in the plot; often, someone notices how similar two characters look and thus figures out they are related to each other.
A Super-Trope of Uncanny Family Resemblance (where the similarity is maintained further along the family tree), Hereditary Hairstyle and Family Eye Resemblance. Compare Identical Grandson (where the similarities allow for reuse of a character design or actor) and Generation Xerox (where not only the appearance but also the personality and experiences are repeated). Contrast The Ugly Guy's Hot Daughter.
Though sometimes exaggerated in fiction, this trope is Truth in Television, thanks to the mechanics behind our genetics and the way they're expressed.
Strong Family Resemblance has been suggested to play 13 roles. Click below to see other actors suggested for each role, and vote for who you think would play the role best.
