When a child succeeds academically, it is only natural that parents would want to congratulate their child. One fairly simple way to do that would be to comment on how "smart" the child is. However, this can do much more harm than good.

Calling a child "smart" portrays intelligence as fixed and unable to be changed, which is problematic for multiple reasons. The first is that it is completely false. The second is that it gives children the self-destructive belief that failing a task means that they are unintelligent and cannot succeed.

Despite what you may have heard and possibly even convinced yourself, intelligence is not fixed. There is no division between "smart people" and "dumb people" that happens at birth and predetermines who can succeed academically and those who cannot.

Consider one of the most famous measures of intelligence: the IQ test. It is true that IQ scores tend to be relatively stable over an individual's life, but that only means that one's IQ "ranking" in relation to others tends not to change very much. That, however, allows for quite a bit of room for changing in IQ score.

For example, in a University College London study, 33 adolescents took IQ tests in 2004 and then again after 3-4 years. 33% of them experienced changes in IQ score: one student's score increased by 21 points, and one student's decreased by 18 points. To make sure that these changes were not the result of measurement error, the researchers conducted MRI scans on the students' brains while they took the test. Examining the results of the scans revealed an association between parts of the IQ test and parts of the brain. The verbal sections of the IQ test were associated with the grey matter density of the left motor cortex, and the non-verbal sections were associated with the grey matter density of the anterior cerebellum.

The point of this study is that intelligence fluctuates based on time, learning and experience, which has been recognized in IQ research for a long time. As stated in the Discover Magazine article "Ignore IQ Tests: Your Level of Intelligence Is Not Fixed for Life," "[t]hose who hang dearly onto the notion that IQ is fixed for life have managed to ignore decades of published research in the field of applied behavior analysis." Also, according to the Psychology Today article "Intelligence Is Still Not Fixed at Birth," "No sensible IQ researcher would say that intelligence is fixed. Anyone who does tell you that is a nutjob. In fact, leading IQ test makers fully acknowledge that people don't have 'an' IQ."

The myth of fixed intelligence has done a lot of damage to our culture. When students believe that their intelligence is fixed, according to Scientific American, "[they] hold an implicit belief that intelligence is innate and fixed, making striving to learn seem far less important than being (or looking) smart. This belief also makes them see challenges, mistakes and even the need to exert effort as threats to their ego rather than as opportunities to improve. And it causes them to lose confidence and motivation when the work is no longer easy for them."

In other words, children who believe that their intelligence is fixed and are told that their performance reflects their intelligence will give up when they fail. The Atlantic's article "Don't Call Kids Smart" explains that "[w]hen people perform well (academically or otherwise) at early ages and are labeled smart or gifted, they become less likely to challenge themselves. They become less likely to make mistakes, because they stay in their comfortable comfort zone and stop growing. And their fixed mindset persists through adulthood."

This effect not only makes sense logically but has been shown in scientific research. For instance, Carol Dweck performed a series of studies with fifth-grade students. She first gave two groups of them an easy test and praised them in different ways. Students in the first group were praised for their intelligence, and those in the second were praised for their effort. After giving them another test that was rigged to fail them, she gave them a third test that was just as easy as the first one: "Those who had been praised for their effort significantly improved on their first score—by about 30 percent. Those who’d been told they were smart did worse than they had at the very beginning—by about 20 percent."

Praising children for being smart, rather than for putting in effort, is extremely counterproductive because it makes them believe that any challenging activity is indicative of poor character and makes them stay in their comfort zone rather than actually becoming smarter by challenging themselves. Because of this, parents should not praise their children for any fixed qualities.

How should parents praise their children, if not by calling them smart? Joy Phenix of ABC News suggests a few possible ways in her article "Why You Shouldn't Tell Your Kids They're Smart":

"Parent: Wow! An A on your test! Why do you think you did well on this? Kid: I don't know. Parent: Because you studied hard, that's why!"

"Kid: I'm never going to get this! Parent: So, do you think you should just give up? Kid: No. Parent: So, what do you think has to happen? Kid: Keep trying and practice. Parent: Yes!"

"Parent: Wow! You really improved on that timed test. You are making so much progress! How is this happening? Kid: Because I practiced so much!"

As a general rule, it is helpful to praise children for things that they can control such as effort, but unhelpful or even counterproductive to praise them for things that are supposedly beyond their control such as so-called fixed intelligence.