This finding only applies in countries which are generally friendly. Most of the data came from Germany and the USA.
The researchers asked people all around the world whether or not they agreed with the statement: “Most people will use somewhat unfair means to gain profit or an advantage rather than lose it”
The research, published in The Journal of Personality and Social Psychology, measured increases in income rather than absolute income so it’s unlikely that the subjects were more miserable just because they were paid less.
The researchers said; “Employees who believe others to be exploitative and dishonest are likely to avoid collaborative projects and forgo the related opportunities”
So miserable people shoot themselves in the foot when it comes to possible career enhancing opportunities. It seems obvious. Who are you likely to ask to join your project – skills being equal – someone you can get along with or the miserable so-and-so in the corner?