Prior literature has found that as uncertainty in a firms information environment increases, optimism increases in equity analysts' earnings forecasts. The studies suggest an economic incentive explanation, commonly called the management-relations hypothesis. However, there is conflicting evidence that managers would prefer pessimistic forecasts and encourage analysts to ''walk-down'' their forecasts to prevent negative earnings surprises. To test these contradictory findings, this study uses an experimental setting to remove economic incentives from the analyst's decision process and isolate the cause of observed bias in analysts' reports. The results of the experiment show that an increase in the perceived uncertainty of the forecasting task results in significantly lower relative optimism in analysts' earnings forecasts. This finding is consistent with a negativity hypothesis and the managementrelations hypothesis extolled in the empirical research. The findings also show that relative forecast optimism bias is positively related to the level of analysts' buy/sell recommendations consistent with more recent findings that suggest that analysts use motivated reasoning (the tendency to process information in a manner that supports one's goal) in their judgments of forecasted earnings and recommendations. Together, these results suggest that analysts consider and use financial information differently depending on their decision goal.