Can psychological aggregation manipulations affect portfolio risk-taking?

"The NBER Bulletin on Aging and Health provides summaries of publications like this. You can sign up to receive the NBER Bulletin on Aging and Health by email. Consistent with the combination of loss aversion and mental accounting, previous laboratory experiments have found that subjects are more willing to invest in risky assets if they are given less frequent feedback about their returns, are shown their aggregated portfolio-level (rather than separate asset-by-asset) returns, or are shown long-horizon (rather than one-year) historical asset class return distributions. In this paper, we find that these manipulations do not significantly increase portfolio risk-taking when subjects are recruited from a broad swath of the population and have hundreds of dollars at stake which must be invested in real mutual funds over a one-year horizon. We do find that relative to when no historical return information is shown, subjects invest more in equities when they see either one-year or long-horizon historical return distributions, suggesting that many individual investors are unaware of how large the historical equity Sharpe ratio is"--National Bureau of Economic Research web site.