Here is a link to a very cool article exploring the role of DRD4, a dopamine receptor gene, and novelty seeking behaviors in vervet monkeys. Dopamine receptors have been explored from multiple perspectives to determine their role in behaviors related to ADHD (e.g. hyperactivity, reinforcement and reward learning, novelty seeking, etc.) This study measured whether either of the two DRD4 alleles in vervet monkeys was associated with an individual's willingness to approach a novel object placed into their living space. The shorter, five repeat variant of the DRD4 gene was found to be associated with novelty seeking. While the alleles found in vervet monkeys do not align with human variants, this research provides evidence that DRD4 is significant in novelty seeking behaviors and serves to further support the body of evidence implicating DRD4 in ADHD.