The Dark Side
Intelligence is static
Leads to a desire to look smart and therefore a tendency to...
People who hold a Fixed Mindset believe that "we are the way we are," but that does not mean that they have less desire than anyone else for a positive self-image. So of course they want to perform well and appear to be smart.
... avoid challenges
A challenge, by definition, is hard, and success is not assured. So rather than risk failing and negatively impacting their self-image, Fixed Mindset individuals will often avoid challenges and stick to what they already know they can do well.
... give up easily when faced with obstacles
This same thinking applies to obstacles. The difference is that challenges are things that they can decide whether to face while obstacles are external forces that get in their way.
... see effort as fruitless or worse
Fixed Mindset individuals ask themselves, "What's the point of working hard and making efforts if afterwards I might still be on square one?" Their worldview tells them that effort is an unpleasant thing that does not really pay dividends, and so the smart thing to do is for them to avoid it as much as possible.
... ignore criticism or useful negative feedback
The Fixed Mindset logically leads people to believe that any criticism of their capabilities is criticism of them as a person. Useful negative feedback is ignored, in the best of cases, and taken as an insult the rest of the time. This usually discourages people who are around a Fixed Mindset individual and, after a while, they stop giving any negative feedback. This further isolates that person from external influences that could generate some change.
... feel threatened by the success of others
FIxed Mindset individual see the success of others as benchmarks against which they will look bad. When others succeed, they will try to convince themselves, and the people around them, that the success was due to either luck (because almost everything is due to luck in teh Fixed Mindset world), or to objectionable actions. They may try to tarnish the success of others by bringing up things completely unrelated ("Yes, but did you know...").
All this confirms a deterministic view of the world.
As a result they may plateau early and achieve less than their full potential.
Fixed Mindset individuals do not reach their fullest potential and their beliefs feed on themselves, forming negative feedback loops. They don't change or improve much of the time, if ever, and so for them this confirms that "we are the way we are."