Objective: Some gambling product messages are designed to inform gamblers about the long-run cost of gambling, e.g., “this game has an average percentage payout of 90%.” This message is in the “return-to-player” format and is meant to convey that for every £100 bet about £90 will be paid out in prizes. Some previous research has found that restating this information in the “house-edge” format, e.g., “this game keeps 10% of all money bet on average”, is better understood by gamblers and reduces gamblers’ perceived chances of winning. Here we additionally test another potential risk communication improvement: a “volatility statement” highlighting that return-to-player and house-edge percentages are long-run statistical averages, which may not be experienced in any short period of gambling. Method: Gambling information format and volatility statement presence were manipulated in an online experiment involving 2,025 UK gamblers. Results: The house-edge format and the presence of volatility statements both additively reduced gamblers’ perceived chances of winning. In terms of gamblers’ understanding, house-edge messages were understood the best, but no consistent effect of volatility statements was observed. Conclusions: The return-to-player gambling messages in current widespread use can be improved by switching to the house-edge format and via the addition of a volatility statement.

In this commentary, we argue that Fried's article, "Lack of theory building and testing impedes progress in the factor and network literature," provides a number of insights that will be very useful for psychologists, but also that he is wishing for psychology to focus on a kind of theory that it cannot generally be expected to produce at this time. As we will explain, Fried asks too much of our models and our theories. In part, this stems from a failure to consistently heed his own warnings about the limitations of statistical models, but it also reflects an overestimation of the kind of evidence and reasoning necessary to develop and test theory. We too believe that psychological research on individual differences should pay attention to theory, but we are more optimistic than Fried about the progress that can be made through a focus on the kind of theory that psychology is actually capable of producing. In order to justify our optimism, we first develop our perspective on the nature of latent variables and then consider how individual-difference researchers should approach theory that has the potential to explain them.