Characterisation of insomnia as an environmental risk factor for asthma via Mendelian randomization and gene environment interaction

Asthma is a complex disease that is reportedly associated with insomnia. However, the causal directionality of this association is still unclear. We used asthma and insomnia-associated single nucleotide polymorphisms (SNPs) and genome-wide association study (GWAS) summary statistics to test the causal directionality between insomnia and asthma via Mendelian randomization (MR) analysis. We also performed a cross-trait meta-analysis using UK Biobank GWAS summary statistics and a gene–environment interaction study using data from UK Biobank. The interaction of genetic risk score for asthma (GRSasthma) with insomnia on asthma was tested by logistic regression. Insomnia was a risk factor for the incidence of asthma, as revealed by three different methods of MR analysis. However, asthma did not act as a risk factor for insomnia. The cross-trait meta-analysis identified 28 genetic loci shared between asthma and insomnia. In the gene–environment interaction study, GRSasthma interacted with insomnia to significantly affect the risk of asthma. The results of this study highlight the importance of insomnia as a risk factor of asthma, and warrant further analysis of the mechanism through which insomnia affects the risk of asthma.

A simple interpretation of undirected edges in essential graphs is wrong

Artificial intelligence for causal discovery frequently uses Markov equivalence classes of directed acyclic graphs, graphically represented as essential graphs, as a way of representing uncertainty in causal directionality. There has been confusion regarding how to interpret undirected edges in essential graphs, however. In particular, experts and non-experts both have difficulty quantifying the likelihood of uncertain causal arrows being pointed in one direction or another. A simple interpretation of undirected edges treats them as having equal odds of being oriented in either direction, but I show in this paper that any agent interpreting undirected edges in this simple way can be Dutch booked. In other words, I can construct a set of bets that appears rational for the users of the simple interpretation to accept, but for which in all possible outcomes they lose money. I put forward another interpretation, prove this interpretation leads to a bet-taking strategy that is sufficient to avoid all Dutch books of this kind, and conjecture that this strategy is also necessary for avoiding such Dutch books. Finally, I demonstrate that undirected edges that are more likely to be oriented in one direction than the other are common in graphs with 4 nodes and 3 edges.

Short telomeres drive pessimistic judgement bias in zebrafish

The role of telomerase reverse transcriptase has been widely investigated in the contexts of ageing and age-related diseases. Interestingly, decreased telomerase activities (and accelerated telomere shortening) have also been reported in patients with emotion-related disorders, opening the possibility for subjective appraisal of stressful stimuli playing a key role in stress-driven telomere shortening. In fact, patients showing a pessimistic judgement bias have shorter telomeres. However, in humans the evidence for this is correlational and the causal directionality between pessimism and telomere shortening has not been established experimentally yet. We have developed and validated a judgement bias experimental paradigm to measure subjective evaluations of ambiguous stimuli in zebrafish. This behavioural assay allows classification of individuals in an optimistic–pessimistic dimension (i.e. from individuals that consistently evaluate ambiguous stimuli as negative to others that perceive them as positive). Using this behavioural paradigm we found that telomerase-deficient zebrafish ( tert − / − ) were more pessimistic in response to ambiguous stimuli than wild-type zebrafish. The fact that individuals with constitutive shorter telomeres have pessimistic behaviours demonstrates for the first time in a vertebrate model a genetic basis of judgement bias.

MP10: ANALYTICAL STYLE PREDICTS RELIGIOUS AND TELEOLOGICAL BELIEF

Purpose of StudyShenhav et al. (2011) found that individual analytical style (reflective vs. intuitive) predicts belief in God or a higher power. Although intuitive thinkers are more likely to have strengthened religious beliefs since childhood, there is no correlation between analytical style and familial religiosity during childhood. This study examines the hypothesis that the link between intuitive thinking and religious belief is part of a broader preference for teleological explanations. We also test a possible mechanism responsible for teleological endorsement: intuitive thinkers may endorse teleological explanations because they confuse causal directionality.Methods UsedA questionnaire comprised of a randomized series of stimuli was administered via Amazon Mechanical Turk. Stimuli included the Cognitive Reflection Test (CRT; Frederick, 2005) to determine analytical style, questions on conditional probability to judge causal reasoning (Kahneman & Tversky, 1977), and a series of true or false questions on various teleological statements (Kelemen et al., 2013). Participants were then asked to rank on a scale from 1–7 the extent to which they believe in the existence of God or a higher power, and the extent to which they believe such a higher power influences events in the world (agency). Statistical analysis was performed using Spearman correlation.Summary of ResultsAs expected, teleological endorsement levels positively predicted belief in agency of a higher power (R=0.28, p<.01) and CRT score negatively predicted teleological endorsement levels (R=−0.24, p<.01). However, no significant correlation was found between CRT performance and tendencies in responding to conditional probability stimuli (R=0.017, p=0.85). Individual belief in agency of a higher power predicts teleological tendencies to a greater extent than religious belief alone (p=0.075) for belief in higher power, compared with p=0.085 for belief in agency of higher power.ConclusionsOur results replicate previous findings that show a relationship between intuitive thinking and religious beliefs and suggest that this may reflect a general preference for teleological explanations. However, the reasons why intuitive thinkers endorse teleological explanations are still unclear.