Observing many researchers using the same data and hypothesis reveals a hidden universe of uncertainty

This study explores how researchers' analytical choices affect the reliability of scientific findings. Most discussions of reliability problems in science focus on systematic biases. We broaden the lens to emphasize the idiosyncrasy of conscious and unconscious decisions that researchers make during data analysis. We coordinated 161 researchers in 73 research teams and observed their research decisions as they used the same data to independently test the same prominent social science hypothesis: that greater immigration reduces support for social policies among the public. In this typical case of social science research, research teams reported both widely diverging numerical findings and substantive conclusions despite identical start conditions. Researchers' expertise, prior beliefs, and expectations barely predict the wide variation in research outcomes. More than 95% of the total variance in numerical results remains unexplained even after qualitative coding of all identifiable decisions in each team's workflow. This reveals a universe of uncertainty that remains hidden when considering a single study in isolation. The idiosyncratic nature of how researchers' results and conclusions varied is a previously underappreciated explanation for why many scientific hypotheses remain contested. These results call for greater epistemic humility and clarity in reporting scientific findings.

From Me to You: Time Together and Subjective Well-Being in the UK

Time together as a family is a crucial dimension of family life. However, its impact on personal happiness is not well understood. I use the United Kingdom Time Use Survey 2014-2015 to study how time spent with partners and children affects daily subjective well-being. Overall, I find that family time, couple time, and time alone with children contributes significantly to mothers' and fathers' well-being. I show that the activities that families share together mediate an important part of the enjoyment of time together but do not entirely explain this association. This suggests that beyond what families do together, families enjoy being together. I find that fathers enjoy family time more than mothers do. I demonstrate that the unequal division of labour during family time explains this discrepancy. I conclude by discussing the recent transformations of intimate relationships.

The social stratification of time use patterns

Time use is both a cause of social inequality and a consequence of social inequality. However, how social class stratifies time use patterns is seldom studied. In this paper, I describe the time use patterns in the years 1983 and 2015 by social class, and gender in the British context. Using sequence analysis methods, I show how the diversity of time use patterns in British society is socially stratified. I find that 13 clusters capture the heterogeneity of time use patterns and that these clusters are associated with social class, gender, and day of the week. These clusters capture patterns of paid and unpaid work schedules, as well as leisure patterns. The results show that men have experienced a reduction of the standard Monday to Friday 8-hr working day, while women have experienced a general increase in this type of schedule. On the other hand, patterns of domestic working days have reduced for women and increased for men. Important differences exist in paid and unpaid work patterns between social classes. Working-class women have experienced an important increase in shift work on weekends. They are also much more likely to be doing unpaid work on weekdays compared to upper-class and middle-class women. Working-class men are more likely to experience non-working days and leisure days on both weekdays and weekends and are more likely to be doing shift work. They are also more often doing unpaid work on weekdays compared to men in upper-class households. Patterns of childcare indicate that all families have increased their childcare time. Men in upper-class households in particular have experienced an important growth in childcare time between 1983 and 2015. I conclude by discussing how time use can further our understanding of social stratification.

Prenatal exposure to ethanol in rats: effects on liver energy level and antioxidant status in mothers, fetuses, and newborns

The fetal alcohol syndrome is a clinical condition that affects newborns from alcoholic mothers. It is not clear, however, whether ethanol consumption during gestation can affect liver functions of fetuses and newborns. In this study, we aimed to assess the effects of ethanol administration on body weight, liver energy level, and antioxidant status of mothers, fetuses, and newborns. Pregnant rats were exposed to ethanol during the third week of gestation. Body weight, survival, and liver concentration of gluthatione (GSH) and adenosintriphosphate (ATP) were measured. No differences were observed in body weight or in liver ATP and GSH between mothers exposed to ethanol and control animals. Conversely, fetuses from rats exposed to ethanol showed a marked decrease in GSH, ATP, and body weight when compared to those from control rats. Newborns exposed prenatally to ethanol were no different from those born to control mothers. This study suggests that an amount of ethanol that is not sufficient to determine a significant effect on mothers can, nevertheless, cause a marked decrease in growth and in liver antioxidant and energy status in fetuses. These parameters, however, return to control value one week after ethanol discontinuation.