A painstaking yearslong effort to reproduce 100 studies published in three leading psychology journals has found that more than half of the findings did not hold up when retested. The analysis was done by research psychologists, many of whom volunteered their time to double-check what they considered important work. Their conclusions, reported Thursday in the journal Science, have confirmed the worst fears of scientists. The vetted studies were considered part of the core knowledge by which scientists understand the dynamics of personality, relationships, learning and memory. More than 60 of the studies did not hold up. The new analysis, called the Reproducibility Project, found no evidence of fraud or that any original study was definitively false. Rather, it concluded that the evidence for most published findings was not nearly as strong as originally claimed. Dr. John Ioannidis, a director of Stanford University's Meta-Research Innovation Center ... said the problem could be even worse in other fields, including cell biology, economics, neuroscience, clinical medicine, and animal research. The report appears at a time when the number of retractions of published papers is rising sharply in a wide variety of disciplines. Scientists have pointed to a hypercompetitive culture across science that ... provides little incentive for researchers to replicate the findings of others, or for journals to publish studies that fail to find a splashy result.