How could self-esteem be unhealthy?
It depends on what it is that makes you feel good about yourself. Do you depend on other peoples' approval to boost your self-esteem? Probably. Most of us do. What matters is how much.
It's unhealthy to have too much of what psychologists call contingent self-esteem - meaning self-esteem that depends on reaching some standard of excellence.
That might seem a good thing, motivating us to reach our goals. Not neessarily.
Contingent self-esteem may motivate us to worry too much about our physical appearance, being popular and out-doing others in business, sport or study. True, it may also motivate us to be virtuous or moral - though possibly because we are conforming to conventional virtues or moral standards, not because we believe in them.
Worried about being popular or admired?
Think of contingent self-esteem as handing our lives over to other people. Others choose our goals. They set the standards for our success. They judge us.
People who depend too much on other peoples' approval are constantly comparing themselves with others - often people they only know about through the media. They are overly concerned with appearances - maybe having the biggest SUV in the office park, keeping up with the fashions and inviting friends and family to their fancy house.
Worried about success?
People with contingent self-esteem can be more ambitious than people who are not driven by the need for other peoples' approval. Generally speaking, it doesn't make them more successful, just less resilient, more anxious and more self-conscious. (One study showed that students who tied their self-esteem to their success in exams were not only no more successful than those who didn't, but more more likely to be in conflict with their lecturers.)
Those who depend too much on others' approval are more likely to abandon their goals, come up with excuses when they have a setback, or only set easy goals, because trying hard and failing would be a serious threat to their identity as a successful person.
So what can we do?
We can focus on the rewards of living according to our values and feeling good about achieving goals that are important to us. We can do our best to shrug off unhelpful comments from those who judge us according to their own standards.
We can also practise self-compassion. It sounds soft, but the rewards are well supported by research: less unhealthy contingent self-esteem, more mindfulness, decreased rumination. (Nothing promotes stress as much as rumination - going over and over the causes of our anxiety.)
We can adopt a growth mindset - seeing life as a journey, not a measure of our worth. With a growth mindset we see setbacks as almost inevitable - and opportunities to learn. We can see those setbacks and failure as evidence that we are like other people - not different.
Keep in mind too that there's a clear link between contingent self-esteem and depression. (We can't yet say that contingent self-esteem causes depression, only that the two are associated - like smoking and cancer.)
Like so much in the psychology of thriving, there's more to self-esteem than most people think.