What Is a Growth Mindset, and Does It Actually Work?

Direct answer: Growth mindset (the belief that abilities can be developed through effort) is grounded in real research, but its school-intervention effects are much smaller than popular claims suggest. A 2018 meta-analysis of 43 studies found near-zero average effects; the largest randomized trial, with 12,490 students, found a modest 0.11 standard-deviation GPA gain, mostly among lower-achieving students.

What Carol Dweck’s Original Research Actually Found

Dweck’s foundational work, including a well-known 1998 study with psychologist Claudia Mueller, tested how children responded to failure after receiving different kinds of praise. Fifth graders praised for intelligence after solving problems became more likely to avoid harder tasks afterward and to misrepresent their scores when they struggled; children praised for effort chose harder tasks and kept trying longer. That lab finding, distinguishing a fixed mindset (believing intelligence is set) from a growth mindset (believing it can be developed), is the real foundation everything else builds on, and it has held up reasonably well in controlled lab settings.

The distinction Dweck drew was never really about optimism versus pessimism. It was about what a child believes happens inside their own head when they struggle. A child with a fixed mindset tends to read failure as information about a ceiling: I hit my limit, this is who I am. A child with a growth mindset tends to read the same failure as information about a process: I have not figured this out yet. That single difference in interpretation, replicated across many small lab studies through the 1990s and 2000s, is what made the theory compelling enough to attract attention far beyond academic psychology.

The open question is whether it holds up the same way once it becomes a brief classroom program delivered to thousands of students at once, which is where the picture gets more complicated. A controlled lab session, run by researchers with a child one at a time, is a very different intervention from a single online module handed to an entire ninth-grade class. Scaling a psychological finding changes it, and the research on that scaled version tells a noticeably more modest story than the original lab work did.

Why Large-Scale School Interventions Show Much Smaller Effects

When researchers tried to scale Dweck’s lab findings into short classroom programs, the results were far weaker than the original studies implied. In 2018, Victoria Sisk and colleagues published two meta-analyses in Psychological Science, one covering 273 studies on the mindset-achievement link and one covering 43 studies testing mindset interventions; both found the overall relationship was weak, with intervention effects close to zero for most students, though somewhat larger for academically at-risk or low-income students.

The largest single study, the National Study of Learning Mindsets (Yeager et al., 2019, Nature), randomly assigned 12,490 ninth graders across 65 public schools to a single under-one-hour online mindset lesson. It found a real but modest effect: a 0.11 standard-deviation gain in core-course GPA among lower-achieving students, with no reliable effect across the full sample. That distinction matters. The study is often cited as proof mindset interventions work, but the honest reading is narrower: a brief, well-designed intervention produced a small, real benefit for a specific subgroup of students who were already struggling, not a universal boost for every student who received it.

A 2019 replication attempt by Yue Li and Timothy Bates, published in the Journal of Experimental Psychology: General, found that the intervention did shift students’ beliefs about intelligence, but that shift did not translate into better resilience after failure, cognitive test scores, or educational attainment. In other words, the program changed what students said they believed about intelligence without reliably changing how they actually behaved when they hit a hard problem. That gap between stated belief and measured outcome is one of the more uncomfortable findings in this literature, because it is exactly the gap a school assembly or a poster campaign cannot see.

A 2023 meta-analysis by Brooke Macnamara and Alexander Burgoyne pushed the estimate even lower, to roughly 0.05 standard deviations, and argued that larger published effects cluster around researchers with a financial stake in mindset programs; other statisticians have since disputed how that conflict-of-interest measure was defined. That dispute is still unsettled in the field, and it is worth naming honestly rather than picking a side: the underlying pattern, that published effect sizes for school mindset interventions keep shrinking as methodology gets stricter, is not seriously contested even by researchers who disagree about why it is happening.

Taken together: growth mindset is a real, measurable psychological pattern, but on its own it is not a reliable lever for closing achievement gaps.

So Should You Still Encourage a Growth Mindset at Home?

Yes, with realistic expectations. The family-level version of this research is better supported than the school-assembly version: praising a child’s strategy and effort rather than labeling them “smart” costs nothing, has no documented downside, and is grounded in Dweck’s original, still-replicated lab findings. When a child brings home a hard math problem they eventually solved, naming the specific thing they did (you tried three different methods before one worked) carries more of that original lab effect than a general comment about intelligence ever did.

What the evidence does not support is treating a poster or a single pep talk about growth mindset as a substitute for what actually moves a struggling student, such as more instructional time, targeted help with a specific skill gap, or one-on-one tutoring. If a child is behind in reading or math, mindset language may help them stay willing to keep trying, but the research says it will not close the gap by itself. The two are not competing approaches. A family that keeps effort-focused praise as a daily habit while also getting a struggling reader real, structured help is applying both what the lab research supports and what the intervention research says is actually needed. A family that treats the mindset talk as the whole plan is asking a small, real effect to do a job it was never shown to do.

Verified growth mindset research against these sources on 2026-07-31: