The current upsurge of interest in research replicability (and the exposure of many failures of reproducibility) has led to a much discussion about the possible role of statistical moderation (i.e., variable × variable interactions) in behavioral and social science. These interactions are so widespread and powerful, it is often argued, that we should hardly be surprised when attempts to reproduce important findings frequently lead to failure. Prior literature provides little empirical evidence about how common powerful moderation is. Using five large-scale behavioral research datasets we sought to shed light on the issue. The data reflected several thousand people engaging in a variety of behaviors over considerable periods of time, and included hundreds of demographic and psychological independent variables (IVs). For each outcome variable, we measured the interaction of every pair of IVs. Many IVs had sizable main effects on behavior, but interactions were usually very small in magnitude. While there is no doubt that interactions can occur in behavioral science contexts, the priors revealed here suggest that this should be postulated as a last, not a first resort.

The utility of shock-absorbing boot and sneaker inserts for reducing the occurrence of lower limb pain among male US Army basic trainees was evaluated. Every other training unit was given inserts. The inserts were issued prior to the start of training when combat boots and sneakers were fitted. According to post-training questionnaires and the participants' medical records, the inserts did not have any preventive effect on occurrence of lower limb problems during training. Five hundred seventeen trainees were issued inserts, 397 were followed but not issued inserts, and 218 were not issued but purchased them on their own. Thirty-eight percent of those issued inserts had lower limb pain problems compared with 29% of those not issued inserts and 38% of those who bought their own. There was no statistical difference between these rates of occurrence. Prior to training, there were minor differences between the groups' scores on physical fitness test scores and run times. These differences disappeared during training so that there were no differences among the groups on either training or clinical variables during or after basic training.

Left ventricular ejection fraction at rest and during treadmill and isometric handgrip exercise were determined in 16 patients with essential hypertension (mean age 47.4 years) before and after therapy. The untreated hypertensive patient showed a linear correlation between mean blood pressure and LVEF (r =0.62, p < 0.01). The relation of sitting, resting LVEF with systolic blood pressure was highly significant (r =0.88, p < 0.001). Prior to therapy no significant change in LVEF in response to exercise was noted. After therapy with captopril, a normal isotonic exercise response occurred consisting of a highly significant increase in ejection fraction (p < 0.0025). Subjects receiving propranolol had a fall in LVEF with isometric stress (p < 0.0025). These data suggest an increased ejection fraction in patients with essential hypertension when all other parameters of the heart are normal and an abnormal response to isotonic exercise which may be reversed with therapy.

Narcissism is unrelated to using first-person singular pronouns. Whether narcissism is linked to other language use remains unclear. We aimed to identify linguistic markers of narcissism. We applied the Linguistic Inquiry and Word Count to texts (k = 15; N = 4,941). The strongest positive correlates were: using words related to sports, second-person pronouns, and swear words. The strongest negative correlates were: using anxiety/fear words, tentative words, and words related to sensory/perceptual processes. Effects were small (each |r| &lt; .10).

SUnlnlaryThermograms showing heat patterns in the trunk of the body were taken of ten intact subjects, seven subjects with incomplete spinal cord injuries (SCI), and fifteen subjects diagnosed as having complete SCIs. Fourteen of the subjects with complete SCIs had a thermal demarcation line across the trunk. This line represented a temper ature gradient of one to 2· 5 degrees Celsius between a relatively warm upper level where sensations were normal and a relatively cool lower level in which sensations were either absent or different from pre-injury sensations. The transition zone was narrow and sharp for ten of the complete SCI subjects but was wide and gradual for the other five complete SCI subjects. The shape and width of the thermal transition zone corresponded to the location and degree of abruptness with which sensations changed from normal to abnormal. One of the subjects diagnosed as having a complete SCI failed to show a significant transition zone. The temperature difference between the upper and lower portions of his trunk was less than one degree Celsius. None of the intact or incomplete SCI subjects produced the transition zone. Only one incomplete SCI subject showed even a minimal difference in temperature between the normal sensation and abnormal sensation levels. A panel blind to the subjects' conditions was unable to differentiate between intact and incomplete SCI subjects but was able to sort complete from incomplete SCI subjects in all but the case with an indistinct transition zone.