He shows substantial knowledge of physics, anatomy, law, history, and forensic anthropology. Despite his high intelligence, he displays a personality with overly rude, narcissistic, and jerkish traits, and acts like he is completely omniscient and more intelligent than everyone else (including Dr. Brennan), not treating his superiors with the respect they deserve. He constantly interrupts them, much to their annoyance.
While he considers himself to have an open mind, this has actually proven to be a disadvantage; during his first case with the Jeffersonian, he became so caught up in the possibility that their victim had developed time travel that he insisted on the team at least considering the possibility that a second set of remains found that bore a striking similarity to their first victim was the corpse of the victim's future self, who had died when he came back in time and changed history so that his past self was killed, rather than consider the more logical explanation that the similarities between the two victims were simply the result of them being related.
In Season 9 Episode 5, The Lady on the List, he is given a bucket list by Angela in order to change his behavior and insult him;
1. Don't be a douche.
2. Really, don't be a douche.
3. Work and play well with others, so I'm not perceived as a douche.
He is strongly disliked, Dr. Brennan even bluntly stating that nobody enjoys his company in The Woman in White. Oliver, together with all the other interns, was invited to Brennan and Booth's wedding. He and Daisy were often seen competing for Dr. Brennan's praise like children. Eventually, Hodgins reminded him that he needed to get along with her because she was part of their "family".
- He eats string cheese to help himself think.
- He is one of the few interns to have a doctorate, he also has a range of Masters degrees in a wide range of subjects.