Human beings are weird - and these studies from 2015 are more than enough proof.
The following 10 studies about the way humans work have been compiled by GeoBeats. They show just how fascinating (and slightly bizarre) the human race is.
10. We sniff out other people's scents
After shaking hands with others, humans are likely to sniff their own hands. This is most likely for information-gathering purposes.
9. People are equipped with a built-in pain reliever
Crossing your middle and index fingers can confuse the brain about which is feeling what. For example, when a cool finger is placed over a burning one, the sensation of heat is diminished.
8. Why do knuckles pop?
After studying MRI scans of knuckles being cracked, doctors found that the cracking sound comes from the formation of a bubble in fluid between the joints.
7. How to rid your brain of annoying songs
Scientists didn't manage to solve the mystery of why irritating songs get stuck in our heads.
But they did figure out that chewing a piece of gum disrupts the pathway between the ear and the brain, which makes you less likely to get a tune stuck in your head for days on end. Winner.
6. Women now weigh as much as men did in the 1960s
The average American woman now weighs as much as the average man did in the 1960s, according to a study.
5. Improve critical thinking skills through sense of smell
When we detect a fishy smell, humans often react with raised suspicions. Researchers discovered a fishy aroma made us more likely to question and examine information before coming to conclusions.
4. Human hair is pretty complex
Scientists discovered a new layer within hair strands which is made up of beta-Carotene, a component not previously known to exist in our kind.
3. Contagious yawning might not apply to psychopaths
Yawning after seeing someone else do the same thing has been shown to be an empathy-related response. But because psychopaths lack empathy, they are less likely to experience the urge.
2. Men really do have a more acute sense of direction
A Norwegian study found that men were quicker to use cardinal directions as a means of orientation than women. They were also able to take a greater number of shortcuts.
Testosterone was found to be a key factor in this.
1. People are smiling more
A survey of yearbook photos, taken between the early 1900s and present day, found that people's smiles have become far larger over the decades.
Researchers attribute this to changing conventions and an increasingly casual attitude towards photography. Say cheese!