Intelligence is most likely to be the criteria for random mating in humans.
Step-by-step explanation:
If random mating is taking place on the conditions that no evolution is taking place the genetic pool will be maintained through generations.
Random mating will be based on intelligence in humans because this is the trait which gets exhibited only when showcased otherwise remains hidden while other characters like personality, appearance and athleticism are phenotypically expressed character.
Random mating is not under the influence of genotype. Intelligence is a trait which needs to be more in human as random mating takes genotype frequency in consideration.