Researchers who refuse to share data with others may【31】others to withhold results from them,【32】a study by health-policy analysts at Harvard Medical School. The study found that young researchers, those who publish【33】, and investigators seeking patents are most likely to be【34】access to biomedical data. It also found that researchers who withhold data gain a【35】for this, and have more difficulty in【36】data from others. The study was【37】by a research team led by sociologist Eric Campbell. The team surveyed 2,366【38】selected scientists at 117 US medical schools. Overall, 12.5 percent said that they had been denied【39】to other academic investigators' data,【40】article reprints, during the past three years. This【41】with findings by the team and other groups. But by examining the【42】of data withholding, the team identified those experiencing the most【43】. For junior staff【44】, the team found that 13.5 percent were denied access,【45】5.1 percent of senior re searchers. The【46】between data withholding and researchers' publishing【47】during the【48】 three years was【49】: 7.7 percent of those who had published 1-5 articles had had data with held from them, but this rose to 28.9 percent for researchers who had published more than 20. Campbell warns, 'Selectively holding back on information from the most【50】researchers could slow down progress in research into the causes and cares of human disease.' (31)