SIGN OF INTELLIGENCE #1: YOU WERE BORN FIRST
Go ahead and rub it in if you’re the oldest child: First-born children exhibit higher IQ scores than their younger siblings, a new University of Edinburgh study suggests. And their superior smarts are evident from the time they are barely a year old.
The researchers followed 5,000 children from pre-birth to the age of 14, and assessed the kids every 2 years with reading, letter-matching, and picture vocabulary tests. They found that while parents with multiple children supported each kid equally on an emotional level, first-borns received more tasks that improved their thinking skills.
SIGN OF INTELLIGENCE #2: YOU HAVE A F**KING TERRIBLE MOUTH
Let those swear words sing—intelligent people use more profane language, a study from Marist College in New York found. For the study, researchers asked the study participants to fire off as many words—in both speaking and writing—as they could in various categories, like obscenities, animals, and words that started with a specific letter. They found that people who were able to list more everyday terms came up with more curse words, too.
SIGN OF INTELLIGENCE #3: YOU MADE YOUR MOTHER SICK
While you were in the womb, that is. After studying expectant moms during pregnancy and their children post-birth, Toronto researchers found that mothers who suffered from morning sickness gave birth to children who scored higher on some intelligence tests than mothers who didn’t spend their mornings hunched over the toilet. The link? It’s possible that women who deal with morning sickness expose their babies to higher levels of pregnancy hormones like estradiol and prolactin, which may result in enhanced fetal brain development, the researchers write.
SIGN OF INTELLIGENCE #4: YOU’RE A NIGHT OWL
Smarter people stay up late, according to one U.K. study. After following more than 20,000 adolescents for eight years, the researchers discovered that those with higher IQs were more likely to become night owls once they reached adulthood than their peers who weren't as smart.
That may be because people with higher cognitive abilities have evolved to override their natural circadian rhythm, or internal clock, that pushed them to settle down to sleep earlier, the researchers write. Our ancestors instinctually slept at night to avoid nocturnal predators—but intelligent, modern humans have evolved beyond those risks, and have adapted to take advantage of nocturnal hours that our ancestors couldn’t.
SIGN OF INTELLIGENCE #5: YOU APPRECIATE ALONE TIME
Hate driving into the city, large events, or tightly packed bars? It might be an indication of your intelligence: After U.K. researchers surveyed 15,000 adults, they found that people with high-IQs were less happy when they lived in a densely populated area, like a big city. What’s more, they also reported higher life satisfaction when they spent less time socializing with their friends than lower-IQ people did.
The introverted-mindset comes down to evolution: Our ancestors lived in tight-knit tribes, and socializing was often necessary for survival, the researchers write. Highly intelligent people have potentially developed beyond the need for that support, meaning they may have adapted to our quickly changing society without depending on their peers.
SIGN OF INTELLIGENCE #6: YOU HAVE A TWISTED SENSE OF HUMOR
Don’t feel bad for offending everyone with your dark since of humor—it might be justified by your brilliance. A warped sense of humor signifies intelligence, according to recent Austrian research. Austrian scientists asked more than 150 people to rate “black humor” cartoons. Then, they measured their verbal and nonverbal intelligence, mood disturbance, and aggressiveness. Participants that preferred the extra vulgar jokes had higher levels of both kinds of intelligence and were less aggressive. That’s because you have to work your mental muscles extra hard to comprehend a twisted joke.
SIGN OF INTELLIGENCE #7: YOU SMOKED POT AS A TEEN
Brainy teens are more likely to experiment with marijuana and alcohol, according to a new University College London study. After following more than 6,000 adolescents from age 11 to 20, the researchers found that once academically-gifted students hit their late teens, they were 50 percent more likely to occasionally use marijuana and nearly twice as likely to persistently use it than their peers who didn’t perform as well academically. They were also more than twice as likely to regularly drink alcohol. But the experimentation stopped with those substances: During their early teens (13 to 17 years old), top students were significantly less likely to smoke cigarettes than their peers who did worse in school.
SIGN OF INTELLIGENCE #8: YOUR DESK IS A MESS
Don’t feel too guilty about that pile of junk crowding up your office: A messy environment promotes creative thinking, according to University of Minnesota research. In one experiment, psychological scientists asked about 50 participants to come up with new uses for Ping-Pong balls. People in messy rooms—think books and papers lying around everywhere—came up with the same amount of ideas as those in cleaner rooms. But their ideas were rated as significantly more interesting and creative by independent judges.