Truthmakers and necessary connections

In this paper I examine the objection to truthmaker theory, forcibly made by David Lewis and endorsed by many, that it violates the Humean denial of necessary connections between distinct existences. In Sect. 1 I present the argument that acceptance of truthmakers commits us to necessary connections. In Sect. 2 I examine Lewis’ ‘Things-qua-truthmakers’ theory which attempts to give truthmakers without such a commitment, and find it wanting. In Sects. 3–5 I discuss various formulations of the denial of necessary connections and argue that each of them is either false or compatible with truthmaker theory. In Sect. 6 I show how the truthmaker theorist can resist the charge that they are committed to necessary exclusions between possible existents. I conclude that there is no good objection to truthmaker theory on the grounds that it violates the Humean dictum.     

Intention to communicate BRCA1/BRCA2 genetic test results to the family.

Guided by the theory of planned behavior, this analysis explores the communication skills of women who had genetic testing for BRCA1 and BRCA2. The key outcome was intention to tell test results to adult first-degree relatives. The theory predicts that global and specific attitudes, global and specific perceived social norms, and perceived control will influence the communication of genetic test results. A logistic regression model revealed that global attitude (p < .05), specific social influence (p < .01), and perceived control (p < .05) were significant predictors of intention to tell. When gender and generation of relatives were added to the regression, participants were more likely to convey genetic test results to female than to male relatives (p < .05) and were also more likely to communicate test results to children (p < .01) or siblings (p < .05) than to parents. However, this association depended on knowing the relative's opinion of genetic testing. Intention to tell was lowest among participants who did not know their relative's opinion. These results extend the theory of planned behavior by showing that gender and generation influence intention when the relative's opinion is unknown.     

Person-environment congruence in relation to career change and career persistence

This study examined Holland’s theoretical proposition, that personality-work environment congruence influences career stability and change, with a sample of 212 career changers (respondents who expressed an intent to change career and had engaged in preliminary career change activity) and 249 career persisters (respondents who indicated an intent to remain in their current career). Independent groups ANCOVA (controlling for age and current career tenure) indicated that career persisters scored higher on congruence than career changers, however, the effect size was within the small to medium range. Repeated-measures ANCOVA indicated, with a medium effect size, that career changers moved towards careers that were more congruent with their personality profiles than their current careers. Practical and theoretical implications are discussed.     

Environmental and Family Associations With Racism1

Environmental and family factors related to racism in college students were investigated. Students (N=114) at a southern liberal‐arts college filled out an extensive survey about childhood activities and family of origin, and 40 of their mothers completed a similar survey. The Attitudes Toward Blacks ( Brigham, 1993 ) scale measured racism. Several hypotheses were supported. Students who exhibited less racism also reported that they made more diverse friends in school, came from a more diverse hometown, had diverse encounters and friendships at an earlier age, and had more positive foreign travel experiences. In addition, more racist students perceived their mothers as being more prejudiced while they were growing up, and they perceived their fathers as being more prejudiced currently. Finally, students judged their mothers as less racist than their fathers, and also reported that their mothers exhibited less racist behaviors than did their fathers. The importance of racially diverse experiences and friendships early in life are discussed as means to decrease racism.     

Line-bisectioning and obstacle avoidance: Evidence for separate strategies

Previous studies have frequently applied a combination of line-bisection tasks (in which participants indicate the middle of a line) and obstacle avoidance tasks (in which participants move their hand between two obstacles) with the aim of revealing perception–action dissociations in certain neurological disorders, such as visual form agnosia and optic ataxia. However, valid conclusions about the underlying processing pathways can only be drawn if participants apply the same strategy in both tasks (i.e. finding the middle between the obstacles). Yet, this assumption has never been tested directly. In this experiment, we investigated whether participants perform obstacle avoidance and line-bisectioning using similar strategies by manipulating the position of the obstacles and the start position of the hand relative to the obstacles. Our results indicate that the lateral hand position during obstacle avoidance does not only vary as a function of obstacle location but also strongly depends on the start position. Moreover, participants showed increased sensitivity to obstacle shifts occurring closer to the hand's start position. In contrast, during line-bisectioning the sensitivity to obstacles shifts was unaffected by the hand's start position. The findings suggest that during obstacle-avoidance the need to keep a safe distance from the obstacles is balanced with the requirement to minimise energetic demands. In contrast, the main intention during line-bisectioning is to move to the perceived midpoint as accurately as possible. The fact that very different constraints underlie trajectory planning in both tasks implies that caution has to be taken when interpreting differences in performance levels.     

18- and 24-month-olds' discrimination of gender-consistent and inconsistent activities

18- and 24-month-olds' ability to discriminate gender-stereotyped activities was assessed. Using a preferential looking paradigm, toddlers viewed male and female actors performing masculine and feminine-stereotyped activities. Consistent with our predictions, and previous research, 24-month-olds, but not 18-month-olds, looked longer at the gender-inconsistent activities than the gender-consistent activities. Results are discussed in terms of toddlers emerging gender stereotypes and perception of everyday events.     

Incidental task sequence learning: perceptual rather than conceptual?

In four experiments we investigated whether incidental task sequence learning occurs when no instructional task cues are available (i.e. with univalent stimuli). We manipulated task sequence by presenting three simple binary-choice tasks (colour, form or letter case decisions) in regular repeated or random order. Participants were required to use the same two response keys for each of the tasks. We manipulated response sequence by ordering the stimuli so as to produce either a regular or a random order of left versus right-hand key presses. When sequencing in both, or either, separate stream (i.e. task sequence and/or response sequence) was changed to random, only those participants who had processed both sequences together showed evidence of sequence learning in terms of significant response time disruption (Experiments 1-3). This effect disappeared when the sequences were uncorrelated (Experiment 4). The results indicate that only the correlated integration of task sequence and response sequence produced a reliable incidental learning effect. As this effect depends on the predictable ordering of stimulus categories, it suggests that task sequence learning is perceptual rather than conceptual in nature.     

When accurate and inaccurate eyewitnesses look the same: a limitation of the ‘pop‐out’ effect and the 10‐ to 12‐second rule

Research has found support for a ‘pop‐out effect’ that occurs when witnesses who accurately identify a criminal from a lineup are faster and uses more automatic processing than inaccurate witnesses who misidentify a foil. We present evidence that this finding may not occur with biased lineups. Witnesses to a mock theft were asked to make a lineup identification and three types of witnesses were compared: (1) accurate witnesses who identified a thief, (2) inaccurate witnesses who misidentified a foil who was more similar looking to the thief than the other lineup foils and (3) inaccurate witnesses who misidentified a foil who was not more similar in appearance to the thief than the other lineup foils. Accurate witnesses who identified the thief and inaccurate witnesses who misidentified a foil more similar to the thief than the other lineup foils were indistinguishable; both were faster, used more automatic recognition processes and were more confident than inaccurate witnesses who identified other foils. Copyright © 2006 John Wiley & Sons, Ltd.