Induced attack during fixed-ratio and matched-time schedules of food presentation

Adjunctive or induced behavior is generated during a variety of schedules of reinforcement. Several theoretical conceptualizations suggest that rate of reinforcement is the primary variable controlling the strength or levels of induced behavior. The operant response requirement within the schedule context has not been extensively studied as a determinant of induced responding. In the present study, levels of induced attack by food-deprived pigeons against restrained conspecifics were compared during response-dependent and response-independent schedules of food presentation equated or yoked interval-by-interval for reinforcement frequency. Experiment 1 compared levels of attack induced by fixed-ratio schedules of key pecking and yoked "matched-time" schedules. Experiment 2 similarly compared chained fixed-ratio 1 fixed-ratio 74 and yoked chained matched-time matched-time schedules. In both experiments, the response-dependent schedules generated greater levels (amount and probability) of induced attack than the response-independent time-based schedules. Thus, the ratio response requirement may be an important determinant of levels of induced responding, and the lower levels of attack observed during the response-independent condition may not be due to the absence of stimuli predicting food presentations. It is concluded that rate of reinforcement is not the sole variable determining levels of induced responding and that response-based and time-based schedules differ in their generation of induced responding.     

Facilitative interactions of model- and experiencebased processes: Implications for type and flexibility of representation

People are often taught using a combination of instruction and practice. In prior research, we have distinguished between model-based knowledge (i.e., acquired from explicit instruction) and experience-based knowledge (i.e., acquired from practice), and have argued that the issue of how these types of knowledge (and associated learning processes) interact has been largely neglected. Two experiments explore this issue using a dynamic control task. Results demonstrate the utility of providing model-based knowledge before practice with the task, but more importantly, suggest how this information improves learning. Results also show that learning in this manner can lead to "costs" such as slowed retrieval, and that this knowledge may not always transfer to new task situations as well as experientially acquired knowledge. Our findings also question the assumption that participants always acquire a highly specific "lookup" table representation while learning this task. We provide an alternate view and discuss the implications for theories of learning.     

Changing perception of average person's risk does not suffice to change perception of comparative risk

The direct method of assessing "unrealistic optimism" employs a question of the form, "Compared with the average person, what is the chance that event X will occur to you?" It has been proposed that when individuals construct their responses to this question (direct-estimates) they focus much more strongly on estimates of their own risk (self-estimates) than on estimates of the average person's risk (other-estimates). A challenge to this proposal comes from findings that interventions that alter other-estimates also change direct-estimates. Employing a novel intervention technique, we tested the possibility that such interventions may indirectly also change self-estimates and that this is what accounts for their effect on direct-estimates. Study 1 (n = 58) showed that an intervention which was designed to (and did) affect other-estimates also affected self-estimates, while Study 2 (n = 101) showed that it affected direct-estimates. Study 3 (n = 79) confirmed that we could modify the intervention so as to maintain the effect on other-estimates, but eliminate that on self-estimates. Study 4 (n = 112) demonstrated that when this was done, there was no longer any effect on direct-estimates. The findings are consistent with the proposal that direct-estimates are constructed largely just out of self-estimates. Implications for heath education programs are discussed.     

Lay knowledge of eyewitness issues: A Canadian evaluation

Lay opinions concerning eyewitness topics were surveyed in three community samples of juror‐eligible participants in Canada. The scientific reliability of these topics had been previously evaluated by eyewitness experts. The first survey assessed participant responses to the identically worded expert items. Participants responded to many statements with greater accuracy than anticipated. Two subsequent surveys assessed the consistency of lay knowledge across variations in the directionality and wording of items and the provision of additional contextual information. Taken together, jury‐eligible participants frequently responded to survey items in ways that closely resembled the responses of experts and suggested awareness and understanding of these topics at levels beyond those previously obtained. Further, the provision of contextual information increased response accuracy and reduced the frequencies of ‘Don't Know’ responses. Deficiencies in knowledge for 50% of the topics were also apparent; however, these topics were frequently those for which the experts themselves had not reached consensus. Copyright © 2008 John Wiley & Sons, Ltd.     

Age differences in recognition of emotion in lexical stimuli and facial expressions

Age differences in emotion recognition from lexical stimuli and facial expressions were examined in a cross-sectional sample of adults aged 18 to 85 (N = 357). Emotion-specific response biases differed by age: Older adults were disproportionately more likely to incorrectly label lexical stimuli as happiness, sadness, and surprise and to incorrectly label facial stimuli as disgust and fear. After these biases were controlled, findings suggested that older adults were less accurate at identifying emotions than were young adults, but the pattern differed across emotions and task types. The lexical task showed stronger age differences than the facial task, and for lexical stimuli, age groups differed in accuracy for all emotional states except fear. For facial stimuli, in contrast, age groups differed only in accuracy for anger, disgust, fear, and happiness. Implications for age-related changes in different types of emotional processing are discussed.     

Early adolescent empathy, parental support, and antisocial behavior

In this two-wave prospective study, the authors investigated whether level of dispositional affective empathy moderated the association between parental support and antisocial behavior in early adolescents. The sample consisted of 823 Dutch boys and girls (mean age = 12.8 years) enrolled in the first year of secondary education. Higher levels of affective empathy were associated with less delinquent and aggressive behavior. Contrary to expectations, structural equation modeling did not indicate that youth with higher levels of affective empathy were susceptible to parental support. Further analyses showed that gender moderated the association between parental support and future delinquent and aggressive behavior. Only for girls, were high levels of parental support associated with lower levels of antisocial behavior.     

Impact of a comprehensive safety program on bicycle helmet use among middle-school children

A bicycle helmet program was evaluated in three middle schools using a multiple baseline across schools design. Two of the three schools had histories of enforcement of helmet use. During baseline many students riding their bikes to and from school did not wear their helmets or wore them incorrectly. A program that consisted of peer data collection of correct helmet use, education on how to wear a bicycle helmet correctly, peer goal setting, public posting of the percentage of correct helmet use, and shared reinforcers, all of which were implemented by the school resource officer, increased afternoon helmet use and afternoon correct helmet use in all three schools. Probe data collected a distance from all three schools indicated that students did not remove their helmets once they were no longer in close proximity to the school, and probe data collected in the morning at two of the schools showed that the behavior change transferred to the morning.     

Color and psychological functioning: the effect of red on performance attainment

This research focuses on the relation between color and psychological functioning, specifically, that between red and performance attainment. Red is hypothesized to impair performance on achievement tasks, because red is associated with the danger of failure in achievement contexts and evokes avoidance motivation. Four experiments demonstrate that the brief perception of red prior to an important test (e.g., an IQ test) impairs performance, and this effect appears to take place outside of participants' conscious awareness. Two further experiments establish the link between red and avoidance motivation as indicated by behavioral (i.e., task choice) and psychophysiological (i.e., cortical activation) measures. The findings suggest that care must be taken in how red is used in achievement contexts and illustrate how color can act as a subtle environmental cue that has important influences on behavior.