We pay more attention to the negative events than to the positive ones. This phenomenon is called the negativity bias.
We would do more to get back $100 that was stolen from us, than to earn $100.
Big storm coming is a bigger news story than 75° and sunny.
One criticism may outweigh many compliments.
This bias exists because paying attention to negative events helps us survive. Throughout evolution it was important to notice threats, because if we didn’t, they could’ve gotten us killed.
In modern life, there are fewer immediate dangers, but our initial instincts still skew towards keeping us safe.
This bias also applies to social relationships. Humans are social creatures who depend on each other. We don’t want to be criticized, because we interpret criticism as rejection (even if it’s well-intentioned), or as a sign of not being good enough (which can lead to some kind of a loss, such as the loss of a job).
Some people try to work their way around this by prefacing the criticism with a compliment. What actually ends up happening is that people get conditioned to expect bad news after you praise them.
It’s not extremely necessary that every single interaction must be positive. What’s more important is the overall quality of the relationship, over the course of many interactions. Relationships need to have many more positive experiences (not necessarily praise) as compared to negative experiences to remain healthy and stable. This applies to all relationships, whether they are professional, romantic relationships or friendships. For example, Dr. John Gottman studied married couples and identified the magic ratio between positive and negative interactions in stable marriages to be 5:1.
The negativity bias also applies to our thoughts. Thoughts naturally tend to gravitate towards negativity. It takes effort to resist this tendency, and shift your thoughts in a more positive direction.