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May 24, 2006

Assignment - Inferring Causation: An Analysis Of The Logic And Conventions Of Research Design

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Unit: HPS771: Research Methods in Psychology A

Topic: Results From The Lecture Attedance Study / Inferring Causation: An Analysis Of The Logic And Conventions Of Research Design

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September 14, 2005

Assignment - Jealousy: Testing Predictions Of The Evolutionary Model

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Unit: HPS121: Introduction to Psychology B
Topic: Jealousy: Testing Predictions Of The Evolutionary Model
Name: Mark Brown
Student No: 100201868
For : Sarah Phillips
Tute time: Friday 11 - 12

Abstract
Evolutionary psychology predicts that men and women will differ in the jealousy evoked by sexual versus emotional infidelity. While evidence for these differences have been found, critics argue that these results may be the cause of gender differences in how the survey question is perceived. 326 undergraduate students were surveyed in an attempt to find further evidence for either the perceptual differences or the evolutionary model. The results suggested that the perceptual differences do not account for findings of the previous research. However, not all of the data supported the evolutionary predictions.

Jealousy: Testing Predictions Of The Evolutionary Model

Until recently, the significance of sexual jealousy may have been overlooked by research psychologists (Buunk, Angleitner, Oubaid, & Buss, 1996). Jealousy has been assumed to be the by-product of other basic emotions (Bunnk et al., 1996) or a pathological phenomenon (Wilson & Daly, 1996). However, recent lines of research have proposed that jealousy may be a specific capacity selected for by evolution. Research in this area provides an opportunity to test certain predictions made on this basis, and is an opportunity to refine a branch of evolutionary theory (Buss, 1995). Further understanding of jealousy may also be useful in forensic psychology, treatment, and counselling given the links between male sexual jealousy and cases of wife battering and homicide (Wilson & Daly, 1996).

From an evolutionary perspective the capacity for jealousy is viewed as an adaptation to problems faced in human evolutionary history (Buss, Larsen, Westen, & Semmelroth, 1992). In species with internal female fertilisation, including humans, only the female can be certain that the child she provides for is her genetic offspring (Buss et al., 1992). As a consequence of paternity uncertainty, males risk investing effort and resources on children that are not their own. Considering that human males invest heavily in their children relative to other species, Buss et al. (1992) have reasoned that in men this evolutionary pressure would strongly select for mechanisms that would prevent cuckoldry. For females, infidelity threatens partial or complete loss of male resources to other women (Buss et al., 1992). Sensitivity and concern for signs that foreshadow the loss of a mate’s investment (signs of a deep emotional attachment developing) would therefore be particularly adaptive for women. Jealousy is thought to be a specific mechanism that solves these problems for both sexes.

Based on this model, Buss et al. (1992) conducted 3 studies, testing the hypothesis that men and women will differ in the amount of distress evoked by sexual versus emotional infidelity. Men were predicted to show more distress over sexual infidelity while women were predicted to find emotional infidelity more upsetting. In two of the studies participants were asked a forced choice question. They were asked to imagine being confronted with either the sexual or emotional infidelity of a partner and to specify which scenario was more distressing. These studies found significant sex differences in the hypothesised direction. A separate study, measuring physiological responses to these scenarios showed similar differences.

Cross-cultural studies using the forced-choice methodology have replicated these findings (Buunk et al., 1996). The predicted sex differences were found in samples from the United States, Germany, and the Netherlands, however, the effect sizes varied. This cross cultural data can be seen as demonstrating that the differences are species wide - an important feature for an evolutionary model (Buss, 1995). The different effect sizes suggest that cultural input may a role in mediating the jealousy mechanism. Critics of the evolutionary model, however, have questioned the interpretations of the data gathered using this paradigm. Harris and Christenfeld (1996) point out that ranging from approximately half the men in the US study to three quarters in the Dutch study do find emotional infidelity more distressing. The evolutionary theory does not explain this phenomenon.

DeSteno and Salovey (1996) have argued that because the research conducted was correlational in nature the results may have been confounded by other variables that correlate with sex. DeSteno and Salovey (1996) hypothesised that participants may perceive one type of infidelity as implying the other; the option that best offers this 'double-shot', therefore, is more likely to be chosen. If men and women differ in their perceptions of the 'double-shot' then this could account for the sex difference found by Buss et al (1992). Variability in how the forced-choice questions are interpreted could also explain the variation within sex groups (DeSteno & Salovey, 1996).

To test the 'double-shot' hypothesis, DeSteno and Salovey (1996) replicated the forced-choice methodology but included an additional measure of the perceived nonindependance of the two options. The results showed that women viewed emotional infidelity as implying sexual infidelity, where as men perceived both types as either independent or equally dependant; as predicted this corresponded to the forced choice data. This new variable was shown to be a better predictor of participants’ response to the forced choice questions than sex.

Using continuous measurements, a separate study failed to reproduce the forced-choice differences (DeSteno & Salovey, 1996), although these results were limited by a small sample size.
DeSteno and Salovey's (1996) results support an alternative to the evolutionary interpretation, and they also suggest that the forced-choice methodology may produce misleading data. In an attempt to resolve some of these issues the following research questions were formulated:

1. Do males and females differ with respect to how they interpret "emotional" and "sexual" infidelity?

2. If we remove the 'double-shot' from the questions posed by Buss et al. (1992) will we still find the sex-differences in responding that Buss et al. (1992) argued were supportive of the evolutionary framework?

3. Can the findings of Buss et al. (1992) be repeated using continuous rather than forced-choice methodology in a larger sample than that investigated by DeSteno and Salovey (1996)?

To investigate these questions, an online survey was made available for a group of over 900 undergraduate psychology students. The participants were asked to imagine discovering an instance of either sexual or emotional infidelity by a real or hypothetical partner. They responded to these scenarios in forced-choice format and on a continuous 7-point scale. In order to control for the 'double-shot' effect, forced-choice questions clearly stated that the alternative type of infidelity was not implied. Participants also rated how likely it would be that their partner could experience each infidelity type independently of the other.

Following from DeSteno and Salovey's (1996) argument, it is hypothesised that the likelihood of a partner forming a deep emotional attachment to someone without becoming sexually attracted to them will be rated lower by women than by men (item 18.3 on the survey).

Since these differences in perception appear to account for the sex differences in choice of infidelity type, it is expected that males and females will respond to the reformulated forced-choice options in similar proportions (item 15).

When responding to each infidelity type on a series of likert scales (items 17 and 18) it is predicted that men will not rate sexual infidelity as more distressing than emotional infidelity, and women will not rate emotional infidelity as more distressing than sexual infidelity.
Method

Participants

Participants were 326 first year psychology students (52 males, 274 females) who volunteered to complete the survey. The mean age was 23.03 years (SD=7.90)

Materials and Apparatus

Participants completed the survey via the Deakin University website using a computer with Internet access and a standard web browser. Questions were largely based on those used in previous studies (Buss et al., 1992; Desteno & Salovey, 1996) and consisted of 25 questions (See Appendix A for a copy of the survey).

Procedure

Students studying Introduction to Psychology B were invited to complete the survey online; the link was made available from within the unit's website. Participation was voluntary and anonymous.
Participants completed a version of the survey worded appropriately for their gender. They were also randomly assigned (based on date of birth) to one of two versions in which the order of infidelity was reversed.

Some questions included sub-questions, bringing the total number of questions to 48.

The Deakin University Human Research Ethics Committee approved these procedures.

Results

In order to test Hypothesis 1, males’ and females’ responses to Question 18.3 on the survey: ‘How likely do you think that it could be that your partner could form a deep emotional attachment with another person without also being sexually attracted to that person’ were compared using an independent samples t-test. Participants answered the question on a likert scale ranging from 1= (extremely unlikely) to 7 (extremely likely). Mean ratings made by each sex are provided in Table 1.

Mean SD
Males 3.87 1.70

Females 3.49 1.68


Table 1. Mean ratings made by men and women for question 18.3

While the data presented in Table 1, with males scoring higher than females on the item, is suggestive of the hypothesised effect, the difference was not significant t(324) =1.48, p>.05. As such, females and males did not differ in the likelihood that they would report that their partners could become emotionally involved with another person without also becoming sexually attracted to that person.
In response to the forced-choice formatted question with the ‘double-shot’ removed, 70.3% of males reported more distress about sexual infidelity, while the slight majority of females, 57.3%, reported more distress about the possibility of a partner’s emotional infidelity. Application of χ2 analysis indicated that this pattern represented a significant relationship between sex and responding χ2 (1, 325)=13.42, p<.05. This ¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬did not support the hypothesis that males and females would have similar rates of responding if the ‘double-shot’ was removed.

Data obtained for the purposes of addressing research question 3, is presented in Figure 1. Examination of Figure 1 indicates that, for males, emotional infidelity in a partner was rated as less distressing than sexual infidelity. Statistical analysis via paired samples t-test indicated that this difference was significant; this result does not support the hypothesis that men would not rate sexual infidelity higher. For females, emotional infidelity in a partner was rated as less distressing than sexual infidelity. Statistical analysis via paired samples t-test indicated that this difference was significant, supporting the hypothesis that women would not rate emotional infidelity as more distressing. Further examination of the results displayed in Figure 1 indicates that, overall, compared with men, women displayed more distress to both types of infidelity.

Figure 1. Levels of distress over sexual vs emotional infidelity reported by male and female participants on the continuous measures.

Discussion

In contradiction of the first hypothesis, women were no more likely to perceive emotional infidelity as implicating sexual infidelity. The second hypothesis was also unsupported, as a significant relationship between sex and response to the forced-choice measure was found, even with the 'double-shot' removed. However, the final hypothesis was partially supported. While the continuous measure showed that men rated sexual infidelity as more distressing, women also rated sexual infidelity as the more distressing scenario.

The results for the first research question undermine the 'double-shot' hypothesis. The inability to replicate the perceptual differences found by DeSteno and Salovey (1996) suggest that the original forced-choice results found by Buss et al. (1992) were not confounded by this variable.
This is supported by the differences found on the reformulated forced-choice question. With the potential for a double-shot' removed the percentage of men choosing sexual infidelity was even greater than in the original study (Buss et al., 1992). While the percentage of women choosing emotional infidelity is not as large as the original study (Buss et al., 1992), it is still supportive of the evolutionary predictions. The differences in effect size between this study and the previous research may be due to the changes to the phrasing of the question, or may reflect cultural differences.

These findings are consistent with the argument that the differences are a direct product of biological sex (and therefore supportive of the evolutionary model). However, it should be noted that they do not prove causation. The results are still limited by the impossibility of randomly assigning the participants to the independent variable (gender) (DeSteno & Salovey, 1996).

Results on the continuous measures of jealousy do not appear consistent with the findings of Buss et al. (1992). While men did rate sexual infidelity as more distressing than emotional infidelity, the results for women appear to contradict the forced-choice results for this and previous studies.
One possible explanation for this discrepancy may be that female participants who chose sexual infidelity as the more distressing scenario may have rated it as significantly more distressing than the alternative; the other female participants may have chosen emotional infidelity because it was only slightly more of a concern. As the forced-choice measure is not sensitive to the magnitude of distress, the strong reaction of a minority would not be reflected in the results. However, when measured on a continuous scale, the average ratings for sexual infidelity could be boosted by a smaller number of high ratings.

Future studies could examine this possibility by expressing the results of the continuous measures in an alternative format. If the data is analysed in terms of which infidelity type each participant rated higher, then these results could be expressed as the proportion of men and women who found each infidelity type more distressing. In this way, the continuous measures can be better compared with the forced-choice data.

Overall this study provides strong evidence against the 'double-shot' hypothesis. However the results of the continuous measure create uncertainty about the implications of the results for the evolutionary model. The continuous measure may or may not be supportive of the predictions. Further research is needed to clarify this issue as well as to test the generaliseability of these findings cross-culturally and in a non-student sample.

References

Buss, D.M. (1995). Evolutionary psychology: A new paradigm for psychological science, Psychological Inquiry, 6, 1-30.
Buss, D.M., Larsen, R.J, Westen, D. & Semmelroth, J. (1992). Sex differences in jealousy: physiology and psychology. Psychological Science, 3, 251-255.
Buunk, B.P., Angleitner, A., Oubaid, V., Buss, D.M. (1996). Sex differences in jealousy in evolutionary and cultural perspective: test from the Netherlands, Germany, and the United States. Psychological Science, 7, 359-363.
DeSteno, D.A. & Salovey, P. (1996). Evolutionary origins of sex differences in jealousy?: the “fitness” of the model. Psychological Science, 7, 367-372.
Harris, C.R. & Christenfeld, N. (1996). Jealousy and rational responses to infidelity across gender and culture. Psychological Science, 7, 378-379.
Wilson, M.I. & Daly, M. (1996) Male sexual proprietariness and violence against wives. Current Directions in Psychological Science, 5, 2-7.

May 01, 2005

Essay - Animal research in psychology

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Unit: HPS111: Introduction to Psychology A
Topic: Animal research in psychology
Name: Mark Brown
Student No: 100201868
For : Alina Holgate
Tute time: Wednesday 12 - 1

Abstract

The ethics of animal research in psychology can be considered in terms of balancing the costs and benefits, in service of the ‘greater good’. Behavioural animal research has brought great benefits, although sometimes the benefits aren’t readily apparent or easily understood. The costs to animal subjects vary greatly depending on the study and are mitigated by a number of factors. I argue that based on a cost benefit analysis, psychological research on animals can be justified, and that the current regulatory system does this effectively.

Justifying Animal Research in Psychology

Animal research in psychology is highly controversial because at it’s heart is an ethical dilemma. Historically, animals were viewed as qualitatively different from humans, allowing for clear moral distinctions (Baldwin, 1993). But beginning in the 19th century, a growing concern for animal rights and animal welfare has led to campaigns against scientific research using animals (Baldwin, 1993). Some campaigners have argued that animals have rights equal to humans, making research on animals immoral (Baldwin, 1993). Meanwhile, the benefits and relevancy of psychological animal research have come under attack (Weiten, 2005), and some researchers have been accused of needless cruelty (Bowd & Shapiro, 1993). There are reasons to place importance on the wellbeing of animals, and, certainly, some research can be highly invasive. But on the other hand, behavioural research on animals can provide great benefits, including improved quality of life and reduced suffering for humans; From this perspective, not conducting research could be seen as allowing suffering to continue. The dilemma, therefore, is one of choosing between two potentially harmful options. What factors should be considered, and how should this decision be made? In this essay, I’ll discuss the benefits of research, the costs to animals, and the suitability of the current regulatory processes. I’ll argue that from a utilitarian perspective, animal research in psychology can be justified, and should therefore be allowed to continue subject to the current checks and balances.

In her overview of the debate, Baldwin (1993) identifies the work of Peter Singer as a key philosophical foundation for the animal rights movement. Singer argues from a utilitarian perspective. He believes that in evaluating the ‘greater good’, animal wellbeing should be included as a factor (Baldwin, 1993). If a non-human organism can experience pain and suffering, then it’s reasonable to count it’s experience in our judgement of what’s ethical. However, it doesn’t follow that invasive research and the sacrifice of animals is never justified. In certain circumstances animal pain and suffering will be off set by even greater benefits. Furthermore, if the impact of an experiment can be minimized, a particular animal research project may still serve the ‘greater good’. From another angle, preventing research could be seen as maintaining the suffering of those who might have benefited from it; Framed in this way, some research may be justified as the lesser ‘evil’. What’s important is weighing both costs and benefits carefully in light of their complexities.

In psychology, there are numerous examples of animal research resulting in significant benefits. While citing the benefits of one particular study doesn’t prove the case for animal research more generally, specific instances are useful for countering broad claims of irrelevancy, as well as demonstrating the possibilities. For example, research on monkeys in the 1960s led to a new rehabilitation technique for patients with some forms of neurological damage (Miller, 1985). Previous research had established that if afferent nerve fibres in an animal’s limb are severed, depriving it of sensation, the animal will no longer use that limb. However, psychologist Edward Taub discovered that by tying back the good arm, a monkey could re-learn, to some extent, to use it’s de-afferented limb. Taub was accused of abuse (Bowd & Shapiro, 1993), however, his discovery led to Constraint Induced Movement Therapy, a successful treatment for stroke, incomplete spinal cord injury, and other brain injuries (Taub & Uswatte, 1999, 2000). Stroke, in particular, affects hundreds of thousands of people each year (Taub & Uswatte, 1999). As such, the benefits of this research are wide spread, and ongoing. This is only one example. Despite the fact that only 7 – 8% of all psychological research involves animals (Weiten, 2005), the list of outcomes are extensive, including treatments for alcoholism, substance abuse, and Alzheimer’s disease (Baldwin, 1993). Against this evidence, criticism on the grounds of irrelevancy isn’t convincing.

However, often the benefits of research on animals may not be readily apparent; This may be the source of much of the criticism against animal research in the field of psychology (Baldwin, 1993). Compared to the immediate, direct impact on the animal, the knowledge and applications of research may seem intangible. However, it is important that the nature of scientific research be taken into account. It is inevitable that some studies will not yield helpful results, as a number of hypotheses may need to be tested before the useful one is proven. Therefore, the inconclusive can still be thought of as contributing to the eventual benefit. Other behavioural research may not produce immediate applications, but can still be justified by the benefits it enables down the line. Classic studies by Skinner and Pavlov are good examples. Their research into conditioning and operant conditioning revealed fundamental psychological principals (Weiten, 2005). These theories are the foundation of behavioural therapies used to treat many conditions including anorexia (Miller, 1985). If the advantages of research are to be given fair consideration, then they need to be weighed in light of these tendencies.

On the other side of the equation, the costs of animal research need a sophisticated examination. A variety of techniques, with varying degrees of invasiveness, may be used in psychological research. Examples range from observations of animal behaviour (for example, the observation of a rat’s lever pressing frequency in a Skinner box (Weiten, 2005)), to sensory deprivation (brain plasticity research in kittens (Weiten, 2005)). How invasive these procedures are will be mitigated by a number of factors: species, number of animals used, anaesthetics, husbandry issues, and euthanasia procedures, may be some of the relevant factors (“Australian code of practice for the care and use of animals for scientific purposes’, 2004). Various scales of invasiveness have been developed to help quantify harm experienced by research animals (‘Using animals in science’, n.d.). Low level invasiveness might involve slight discomfort and mild anxiety, while on the more severe end of the scale, animals may be subjected to prolonged pain and severe distress (‘Using animals in science’, n.d.). An evaluation of the impact of research on animals needs to account for these varying levels of severity.

The current ethical processes are well suited to weighing these costs and balancing them against the benefits. In Australia, the use of animals in psychological research is covered by the ‘Australian code of practice for the care and use of animals for scientific purposes’ (2004). The code of practice provides extensive guidelines, as well as a system of Animal Ethics Committees (AECs). Any research using animals must receive authorisation from an AEC, and each committee must include veterinary, research, and animal welfare experts. This ensures that judgements can be made in the light of sophisticated scientific understanding, based on the latest evidence. Furthermore, one member of the committee must be independent of the research institution and not involved in science; This ensures a measure of independence.

The code of practice pressures researchers to raise animal welfare standards and adjust their methods to minimize harm. It emphasises the principles of the three Rs – “The replacement of animals with other methods, the reduction in the number of animals used, and the refinement of techniques used to reduce the adverse impact on animals” (Australian code of practice for the care and use of animals for scientific purposes’, 2004). Researchers must justify their methods in the light of these principals. For example, in line with the ‘replacement’ principal, research proposals submitted to AECs must include a list of alternative methods and a justification for why these can not be used. If researchers want to be sure of receiving approval, it’s in their interest to ‘replace, reduce, and refine’. As methods improve, AECs can gradually tighten their standards, and in this way, improve animal welfare long term.

AECs have discretion in how they apply guidelines to each individual case. This is an important feature, however, animal rights activists may feel uncomfortable with the flexibility of this system. The code of practice (2004) makes frequent use of indefinite phrases like “only when necessary” and “if essential” – terms difficult to operationally define. In the minds of activists and the general public, this may seem dangerously unclear. Yet, while absolute rules are easier, they can not take into account every circumstance; they can’t account for the latest scientific knowledge, or anticipate the latest research methodologies. An active and flexible regulatory system has the best chance of being ethical, because it’s able to deal with the subtleties of each individual case.

In the end, the question of animals used in psychological research will always be, to some degree, a dilemma. As the success stories show, the benefits of research can be considerable, but so too can the costs, and both are difficult to quantify. For any particular research proposal, there may be no objective way of calculating what’s in the ‘greater good’. How many rehabilitated stroke patients equal one de-afferented monkey? As the APA acknowledges (1990, cited in Baldwin, 1993), it is essentially a matter of conscience. However, the current regulatory system has characteristics that facilitate and ethical balance: Animal Ethics Committees are expert, concerned about animal welfare, and independent. They make case by case judgements based on a variety of detailed information. Meanwhile, the code of practice encourages researchers to minimize harm and replace animal research with other methods.

A culture of concern for animal welfare should be fostered within the psychological community, and researchers should make every effort to minimize harm. Decisions regarding animal research should be made individually, based on sophisticated analyses of both the costs and benefits. Accordingly, I recommend that, subject to the current regulatory processes, research on animals in psychology should be allowed to continue.

References

Australian code of practice for the care and use of animals for scientific purposes (2004). Canberra ACT: Australian Government. Retrieved April 1, 2005 from http://www7.health.gov.au/nhmrc/publications/pdf/ea16.pdf
Baldwin, E. (1993). The case for animal research in psychology. Journal of Social Issues, 49, 121–131.
Bowd, A. D., & Shapiro, K. J. (1993). The case against animal research in psychology. Journal of Social Issues, 49, 133–142.
Miller, N. E. (1985). The value of behavioural research on animals. American Psychologist, 40(4), 423 – 440.
Taub, E. & Uswatte, G. (1999). Constraint-induced movement therapy: a new family of techniques with broad application to physical rehabilitation – a clinical review. Journal of Rehabilitation Research & Development, 36(3), 237 – 251.
Taub, E., & Uswatte G. (2000). Constraint-induced movement therapy based on behavioural neuroscience. In R. G. Frank & T. R. Elliot (Eds.), Handbook of rehabilitation psychology (pp 475-496). Washington, DC: American Psychological Association.
Using Animals in Science (n.d.) Retrieved April 1, 2005 from http://www.adelaide.edu.au/ANZCCART/text/
Weiten, W (2005). Psychology, Themes and Variations: Briefer Version (6th edition). Belmont CA: Wadsworth/Thomson Learning.