Donald H. Thor

Sex Differences in the Sense of Time: Failure to Replicate a 1904 Study

McDougall ( 1904), Yerkes and Urban ( 1906), and other early investigators reported sex differences in time estimation by human Ss, and more recent studies ( Loehlin, 1959) have reported no difference. This replication of McDougalls study followed his procedure as reported with the addition of more Ss and variables. Forty male and 78 female students in introductory psychology estimated four intervals (15, 30, 60, 90 sec.) under four conditions (listening to E read, crossing our 77zs, waiting, counting) by the method of verbal estimation at one of five sessions throughout the day. Differences between mean estimates given by males and those given by females were not significant for any of the conditions and were opposite in direction to what would be expected from McDougalls resulcs. Our obtained differences among the conditions were similar in rank but different in magnitude. McDougalls Ss overestimated all intervals with one exception; the present Ss underestimated all intervals. Additional hypotheses investigated concerned the influence of the time of day at which the estimates were made (Thor & Baldwin, 1965), the effect of the onset of the menstrual cycle, and the importance of psychosexual role identification (PRI) as measured by the Gough femininity scale (Gough, 1952). None of these variables s~gn~ficantly affected time estimates of men and women. However, the relation of b~ological sex and scores on PRI needs particular clarification in fumre research. Assuming the early studies were accurate, Loehlins hypothesis of changing cultural roles as a determinant of time perception may be essentially cotrecc.

Morphine induced fighting and prior social experience

Six groups of normally docile laboratory rats received morphine injections (to 600 mg/kg/day), placebo injections, or no injections under social or isolated conditions for 6 days. Postwithdrawal intragroup fighting was then monitored for 168 h by automated recording of loud vocalizations. Morphine-treated groups spontaneously began sustained (30 h) fighting 3 days after terminal injections, with greatest fighting observed in the group receiving the drug under social conditions.

A circadian variable in self-exposure to light by the rat

When given control over illumination, a rat changes his light or dark condition with a rate that has a circadian periodicity. In isolation, with temperature and humidity controlled, a gradual and systematic phase shifting occurs that renders periodic, exogenous cues an implausible explanation. A near 24 h periodicity in need for stimulus change is implied by data. No light-dark cycle comparable to the day and night rhythm was obtained.

Drug withdrawal and fighting in rats

Rats were given the opioid drug etonitazene in drinking water on a schedule of increasing concentration to 90 mcg/ml. All animals then receiving dextroamp he famine injections during withdrawal exhibited vigorous, periodic fighting for 288 h post withdrawal.

Time of Day Estimates at Six Times of Day under Normal Conditions

75 adults were asked to estimate the correct time of day without reference to clocks at each of 6 times of day from 8:00 A.M. to 8:00 P.M. Significant group mean differences were found, with underestimation of correct time at mid-day and overestimation at early (8:00–10:00 A.M.) and later (6:00–8:00 P.M.) times of day.

Temporal discrimination as a function of total presentation time

Two triangles (Δ and ∇) were presented successively at the same spatial locus for binocular viewing. Manipulation of stimulus duration and interstimulus interval revealed that accuracy in discriminating order is dependent upon total time (S1 + ISI + S2) and that the discrimination threshold (75% correct) is approximately 100 msec.

Observer strategies in dichoptic viewing of successive stimuli

Enhanced ability to correctly perceive order of brief visual stimuli presented dichoptically may be interpreted as learning by the observer to adopt an appropriate strategy.

Morphine-amphetamine-induced fighting and interim socialization

Traumatic and lethal fighting among male rats can be induced by a single moderate dose of amphetamine given during withdrawal from morphine. Socialization with other rats during the interval between terminal morphine and amphetamine modifies the course of subsequent aggressive behavior. Fighting is prolonged for rats maintained in isolation during the interdrug interval.

Chemical suppression of fighting in the Siamese fighting fish

Siamese fighting fish will not fight when paired with another male after a 48 h exposure to a 1 mg/cc solution of diethylamine HC1. Suppression of fighting is reversible with duration of suppression related to concentration of diethylamine HC1 in the exposure solution. Loss of aggression is accompanied by vigorous retreat or escape behavior when confronted by an opponent.