Individual Differences

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Individual Differences

Individual differences research is a branch of psychology concerned with how and why individuals differ in psychological traits. Increasingly, research has focused on the importance of these traits to life outcomes, values, psychopathology, and socially relevant behaviours. The Differential Psychology lectures of Psychology 2 follow from and build on the lectures of Psychology 1. The lectures will cover the two most widely studied forms of individual differences, namely cognitive abilities and personality traits. The first two-thirds of this topic will cover how these individual differences are measured, how they are hierarchically organized, and their genetic bases and developmental trajectories. The final third of the topic will cover the association between individual differences in cognitive abilities and personality to other measures. Finally, because humans are animals, and great apes in particular, whenever it makes sense to do so, I will highlight my research and the research of others on cognitive abilities and personality traits in nonhuman primates.

The lectures are accompanied by a 1-hour tutorial. The lab related to these lectures will be on literature database search and summarizing (addressed in the lecture that takes place before the Individual Differences lectures).

Lecture 4:
Measuring psychological constructs
To study individual differences either in personality or intelligence we need to find a way to measure them. This lecture will cover the basics of how scientists measure psychological constructs.
50 George Square, Lecture Theatre G.03
Monday, 23 September, 2019 - 11:10 to 12:00
Lecture 5:
Introduction to psychological tests
Having discussed the basics of how scientists measure psychological constructs, we will now go a step further and use these concepts to explore the rationale behind psychological tests and how can these be employed to measure individual differences.
David Hume Tower, Lecture Theatre C.
Tuesday, 24 September, 2019 - 11:10 to 12:00
Lecture 6:
A paradigmatic example: the trait approach
Individuals differ in as many different ways as you can imagine but scientists have limited time and resources to study these. In this lecture will discuss in some detail the trait approach, aiming to capture these differences as efficiently and comprehensively as possible.
Appleton Tower, Lecture Theatre 5.
Thursday, 26 September, 2019 - 11:10 to 12:00
Lecture 7:
Development, Maturity, Cognitive aging and personality change
As people age, they change in both abilities, such as intelligence, but also in their personality. However, differences are nonetheless remarkably stable. This lecture will cover how this is possible and also will review different theories for why people change.
50 George Square, Lecture Theatre G.03
Monday, 30 September, 2019 - 11:10 to Wednesday, 30 October, 2019 - 12:00
Lecture 8:
Can we tease apart nature and nurture?
Having measured individual differences, we wish to know why individuals differ from one another. This lecture will cover research that seeks to understand whether these differences come about because of different ways in which people are reared, social class, unique environmental influences, genetic influences, or some combination of these.
David Hume Tower, Lecture Theatre C.
Tuesday, 1 October, 2019 - 11:10 to 12:00
Lecture 9:
Galton's dangerous idea: Intelligence, personality, and life outcomes
As we have discussed up until now, individual differences summarize a wide range of abilities, behaviours, thoughts, and feelings. In this lectures will cover approaches to the study of intelligence and the association with life outcomes.
Appleton Tower, Lecture Theatre 5.
Thursday, 3 October, 2019 - 11:10 to 12:00
Learning Outcomes: 

By the end of the course, students should be able to understand the above-described course content. They should also be ready to understand why measuring individual differences in these traits is important and to identify problems with some studies that do not do so. They should also understand the challenges pertaining to the research into individual differences.


Main Textbook: This is available in the library. 

  • Funder, D.C., (2016). The personality puzzle Seventh edition, International student., New York, N.Y. ; London: W.W. Norton & Company.

Lecture 1

  • Funder Chapter 1 and 2.
  • Cronbach, L. J., & Meehl, P. E. (1955). Construct validity in psychological tests. Psychological Bulletin, 52, 281-302.

Lecture 2

  • Funder Chapter 3

Lecture 3

  • Funder Chapter 6
  • Digman, J. M. (1990). Personality structure: Emergence of the Five-Factor Model. Annual Review of Psychology, 41, 417-440.

Lecture 4

  • Funder Chapter 7
  • Terracciano, A., Costa, P. T., & McCrae, R. R. (2006). Personality plasticity after age 30. Personality & Social Psychology Bulletin, 32, 999–1009.

  • Roberts, B. W., Wood, D., & Smith, J. L. (2005). Evaluating Five Factor Theory and social investment perspectives on personality trait development. Journal of Research in Personality, 39, 166-184.

Lecture 5

  • Funder Chapter 9
  • Bouchard, T. J., Jr. (2014). Genes, Evolution and Intelligence. Behavior Genetics, 44, 549-577.
  • Bouchard, T. J., Jr., & Loehlin, J. C. (2001). Genes, evolution, and personality. Behavior Genetics, 31, 243-273.

Lecture 6

  • Deary, I. J. (2012). Intelligence. Annual Review of Psychology, 63, 453-482. doi: 10.1146/annurev-psych-120710-100353
  • Deary, I. J., Weiss, A., & Batty, G. D. (2010). Intelligence and personality as predictors of illness and death. Psychological Science in the Public Interest, 11, 53-79.
  • Ozer, D. J., & Benet-Martínez, V. (2006). Personality and the prediction of consequential outcomes. Annual Review of Psychology, 57, 401-421.


Further reading:

Asbury, K., & Plomin, R. (2013). G is for genes: The impact of genetics on education and achievement. Chichester, UK: John Wiley & Sons.

Costa, P. T., Jr., & McCrae, R. R. (1982). An approach to the attribution of aging, period, and cohort effects. Psychological Bulletin, 92, 238-250.

Costa, P. T., Jr., & McCrae, R. R. (2002). Looking backward: Changes in the mean levels of personality traits from 80 to 12. In D. Cervone & W. Mischel (Eds.), Advances in personality science (pp. 219-237). New York, NY: Guilford.

Cronbach, L. J. (1957). The two disciplines of scientific psychology. American Psychologist, 12, 671-684.

Hunt, E.B., (2011). Human intelligence, Cambridge; New York, N.Y.: Cambridge University Press.

Judge, T. A., Higgins, C. A., Thoresen, C. J., & Barrick, M. R. (1999). The Big Five personality traits, general mental ability, and career success across the life span. Personnel Psychology, 52, 621-652.

McCrae, R. R., Terracciano, A., & 78 Members of the Personality Profiles of Cultures Project. (2005). Universal features of personality traits from the observer's perspective: Data from 50 cultures. Journal of Personality and Social Psychology, 88, 547-561.

Nettle, D. (2009). Personality: What makes you the way you are. Oxford: Oxford University Press.

Pinker, S. (2003). The blank slate: The modern denial of human nature: Penguin.

Ritchie, S. J. (2015). Intelligence: All that matters: Hodder & Stoughton.

Rowe, D. C., Vesterdal, W. J., & Rodgers, J. L. (1999). Herrnstein's syllogism: Genetic and shared environmental influences on IQ, education, and income. Intelligence, 26, 405-423.

Scarr, S., & McCartney, K. (1983). How people make their own environments: A theory of genotype -> environment effects. Child Development, 54, 424-435.

Schwartz, J. A., Savolainen, J., Aaltonen, M., Merikukka, M., Paananen, R., & Gissler, M. (2015). Intelligence and criminal behavior in a total birth cohort: An examination of functional form, dimensions of intelligence, and the nature of offending. Intelligence, 51, 109-118.

Steel, P., Schmidt, J., & Shultz, J. (2008). Refining the relationship between personality and subjective well-being. Psychological Bulletin, 134, 138-161.

Widiger, T. A., & Trull, T. J. (1992). Personality and psychopathology: An Application of the Five-Factor Model. Journal of Personality, 60, 363-393.