Some personality traits and life experiences have been linked to certain cognitive abilities in research, but none of them can determine whether a person is “smarter than average” on their own. Intelligence is complex and influenced by genetics, education, environment, and experience. Still, studies have found interesting associations with several common traits.

Research suggests that firstborn or only children may perform slightly better on some cognitive tests, possibly because they receive more one-on-one attention early in life. Some studies have also found that left-handed people may excel in certain creative or problem-solving tasks, although the differences are generally small. Night owls have been linked in some research to creative thinking and reasoning skills, but sleep habits alone do not measure intelligence.

A good sense of humor has also been associated with creativity and verbal ability. Successfully making others laugh often requires quick thinking, timing, and the ability to connect ideas in unexpected ways. Likewise, some studies have found that introverted individuals are slightly overrepresented in gifted populations, though both introverts and extroverts can be highly intelligent and successful.

These findings describe general trends rather than rules. Being left-handed, funny, introverted, a night owl, or a firstborn does not automatically make someone more intelligent, just as lacking those traits does not make someone less capable. Intelligence comes in many forms, including creativity, emotional understanding, practical skills, and problem-solving, and no single personality trait can accurately define a person’s overall abilities.