Psychologists typically measure beliefs and preferences using self-reports, whereas economists are much more likely to infer them from behavior. Prediction markets appear to be a victory for the economic approach, having yielded more accurate probability estimates than opinion polls or experts for a wide variety of events, all without ever asking for self-reported beliefs. We conduct the most direct comparison to date of prediction markets to simple self-reports using a within-subject design. Our participants traded on the likelihood of geopolitical events. Each time they placed a trade, they first had to report their belief that the event would occur on a 0–100 scale. When previously validated aggregation algorithms were applied to self-reported beliefs, they were at least as accurate as prediction-market prices in predicting a wide range of geopolitical events. Furthermore, the combination of approaches was significantly more accurate than prediction-market prices alone, indicating that self-reports contained information that the market did not efficiently aggregate. Combining measurement techniques across behavioral and social sciences may have greater benefits than previously thought.

Surveys based on self-reported hygiene-relevant routine behaviors have played a crucial role in policy responses to the COVID-19 pandemic. In this article, using anchoring to test validity in a randomized controlled survey experiment during the COVID-19 pandemic, we demonstrate that asking people to self-report on the frequency of routine behaviors are prone to significant measurement error and systematic bias. Specifically, we find that participants across age, gender, and political allegiance report higher (lower) frequencies of COVID-19-relevant behaviors when provided with a higher (lower) anchor. The results confirm that such self-reports should not be regarded as behavioral data and should primarily be used to inform policy decisions if better alternatives are not available. To this end, we discuss the use of anchoring as a validity test relative to self-reported behaviors as well as viable alternatives to self-reports when seeking to behaviorally inform policy decisions.

The present study examined the effect of analytical thought priming on individual secular beliefs. In Study 1 (N = 64), we employed analytical thinking priming and examined whether such priming can influence the participants’ endorsement of secular belief. In Study 2 (N = 85), we employed another form of treatment condition to enhance analytical thinking and explored what components of secular beliefs were most affected by such condition. The results of both studies showed that participants primed to think with an analytic style possess higher secular belief, but not for all the domains of secular belief. We focused the discussion on the implications of these findings and the strength of secular belief measure.

The association between birth weight and later life outcomes is of considerable interest in life-course epidemiology. Research often relies on self-reported measures of birth weight, and its validity is consequently of importance. We assessed agreement between self-reported birth weight and official birth records for Norwegian twins born 1967–1974. The intraclass correlation between self-reported birth weight and register-based birth weight was 0.91 in our final sample of 363 twins. It could be expected that 95% of self-reported birth-weight values will deviate from official records within a maximum of +446 grams and a minimum of −478 grams — around a mean deviation of 16 grams. Self-reported birth weight had a sensitivity of 0.78–0.89 and a positive predictive value of 0.59–0.85, and an overall weighted kappa of 0.71. We further assessed agreement by conducting two linear regression models where we respectively regressed self-reported birth weight and register-based birth weight on adult body mass index, a known association. The two models were not significantly different; however, there were different levels of significance in parameter estimates that warrant some caution in using self-reported birth weight. Reliability of self-reported birth weight was also assessed, based on self-reports in another sample of twins born 1935–1960 who had reported their birth weight in two questionnaires 34 years apart. The intraclass correlation was 0.86, which indicates a high degree of reliability. In conclusion, self-reported birth weight, depending on context and age when birth weight was reported, can be cautiously used.

High dietary Na intake is associated with multiple health risks, making accurate assessment of population dietary Na intake critical. In the present study, reporting accuracy of dietary Na intake was evaluated by 24 h urinary Na excretion using the EPIC-Soft 24 h dietary recall (24-HDR). Participants from a subsample of the European Food Consumption Validation study (n 365; countries: Belgium, Norway and Czech Republic), aged 45–65 years, completed two 24 h urine collections and two 24-HDR. Reporting accuracy was calculated as the ratio of reported Na intake to that estimated from the urinary biomarker. A questionnaire on salt use was completed in order to assess the discretionary use of table and cooking salt. The reporting accuracy of dietary Na intake was assessed using two scenarios: (1) a salt adjustment procedure using data from the salt questionnaire; (2) without salt adjustment. Overall, reporting accuracy improved when data from the salt questionnaire were included. The mean reporting accuracy was 0·67 (95 % CI 0·62, 0·72), 0·73 (95 % CI 0·68, 0·79) and 0·79 (95 % CI 0·74, 0·85) for Belgium, Norway and Czech Republic, respectively. Reporting accuracy decreased with increasing BMI among male subjects in all the three countries. For women from Belgium and Norway, reporting accuracy was highest among those classified as obese (BMI ≥ 30 kg/m2: 0·73, 95 % CI 0·67, 0·81 and 0·81, 95 % CI 0·77, 0·86, respectively). The findings from the present study showed considerable underestimation of dietary Na intake assessed using two 24-HDR. The questionnaire-based salt adjustment procedure improved reporting accuracy by 7–13 %. Further development of both the questionnaire and EPIC-Soft databases (e.g. inclusion of a facet to describe salt content) is necessary to estimate population dietary Na intakes accurately.

The present paper aimed to examine questionnaire response patterns and objective task-based test behavioral patterns in order to analyze the differences people show in consistency. It is hypothesized that people tend to be more consistent when talking about themselves (when describing themselves through verbal statements) that when they solve a task (when behaving). Consistency is computed using the π* statistic (Hernandez, Rubio, Revuelta, & Santacreu, 2006). According to this procedure, consistency is defined as the value and the dimensionality of the latent trait of an individual (θ) remaining invariant through out the test of. Participants who are consistent must show a constant θ and follow a given response pattern during the entire course of the test. A sample of 3,972 participants was used. Results reveal that 68% of participants showed a consistent response pattern when completing the questionnaire. When tackling the task-based test, the percentage was 66%. 45% of individuals showed a consistent pattern in both tests. Implications for personality and individual differences assessment are discussed.