They were all CEOs, so had gotten to quite senior positions, so an admittedly biased sample.

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Yet, when we survey participants at IMD, which is probably a much-biased sample because of the corporate seniority of the people involved, the estimates of talent under-utilization are shocking.

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The sample size is small and biased toward press who prefer to use personal Gmail accounts over professional addresses.

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"We do seem to be seeing an increased rate in athletes who have early and moderate stage CTE, " said McKee, adding the caveat that the BU sample is autopsy-based and therefore inherently biased.

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