The SAGE Handbook of Personality and Individual Differences

Volume II: Origins of Personality and Individual Differences

Virgil Zeigler-Hill, Todd K. Shackelford, Virgil Zeigler-Hill, Todd K. Shackelford, Author

• Publisher: SAGE Publications Ltd
• Year: 2018
• Print ISBN: 9781526445186
• eBook ISBN: 9781526451170
• Edition: 1
• Topic: Psychology
• Subtopic: History & Theory in Psychology
• Index: Psychology

The examination of personality and individual differences is a major field of research in the modern discipline of psychology. Concerned with the ways humans develop an organised set of characteristics to shape themselves and the world around them, it is a study of how people come to be 'different? and 'similar? to others, on both an individual and a cultural level. This volume focuses on the multiple origins of personality and individual differences, in chapters arranged across three thematic sections: Part 1: Biological Origins of Personality and Individual Differences Part 2: Developmental Origins of Personality and Individual Differences Part 3: Environmental Origins of Personality and Individual Differences With outstanding contributions from leading scholars across the world, this is an invaluable resource for researchers and graduate students.

Part I Biological Origins of Personality and Individual Differences

1 Hormonal Influences on Personality and Individual Differences

Jennifer Guinn Sellers

Thanh Thanh L. Nguyen

I became a huffer, a grunter, a screamer. Anyone who frequents gyms knows those guys who make ungodly noises while hurling weights around. I'd always found their displays childish and tended to look away, as I would from a toddler having a tantrum in a supermarket. So imagine my surprise to find myself bellowing, shrieking, groaning. A silverback gorilla's mating ritual: I wanted everyone to know I was the biggest [expletive] in the place. Craig Davidson

This is what happens to you on steroids, Esquire

Craig Davidson is a writer, and like many writers, he prefers to draw from his experiences when he is developing characters. So when he began to develop a story about a fighter, one who would do anything necessary to win his battles, he decided to embark on a month long journey of injecting himself with steroids. He thought the synthetic form of testosterone he plunged into his muscles would allow him to gain the strength and power fighters need; his research had indicated that was many fighters’ motivation at least. What Davidson did not anticipate, however, was that the synthetic hormone he was injecting into his bloodstream did more than just allow him to gain muscle mass more easily. He also began feeling about, acting in, and perceiving his environment differently. As the above quote illustrates, he was acting in a way that just a month prior, he would have thought were the behaviors of a completely different person. He had changed. The hormones had altered his personality.

Hormones, it turns out, are important contributors to our personality. Many hormones exert an influence on our motivations, moods, and relationships with other people, to list a few of their contributions, in addition to their major known biological function, such as carbohydrate metabolism and tissue development. Of course, normally, hormones are allowed to respond to our internal and external environments, something that Davidson's experience with hormone injection inevitably cannot portray. Thus, our understanding of the role of hormones on personality is far more nuanced than anecdotal influences of steroid abusers could suggest. In this chapter, we will discuss what hormones are and how they are assessed; as well as point out ways this approach to assessing personality differs from more traditional personality assessment techniques. Although using hormones to predict behavior – especially when these hormones can be experimentally manipulated – provides many exciting opportunities, they also pose unique challenges. We will then give a synopsis of the current state of our understanding of the influences of commonly studied hormones on personality. For the purposes of this chapter, however, we will limit our discussion of the literature to studies that focus on human participants. Although we are able to learn many things about human personality through comparative research (Gosling, 2001), inclusion of this literature is beyond the scope of what we are able to discuss. Additionally, we will limit our discussion of hormones to those found outside the central nervous system and to their peripheral effects. Most research conducted with humans does not test for hormones in the central nervous system as the method of assessment involves the use of a spinal tap to withdraw cerebrospinal fluid, a highly invasive procedure. Researchers wishing to learn more about the influence of a specific hormone on personality or effects within the central nervous system should also look to studies with non-human animals as much of our mechanistic understanding, in addition to the primary basis for early work with humans, builds off this literature.

Hormones and how they are measured

Broadly speaking, hormones are chemicals produced in one part of the body that have to travel to a target receptor site in a location separate from where they are produced. Although research into the role of hormones on personality is relatively recent, it is not a new proposition that a biological agent moving throughout the body affects our personality. Greek physicians such as Hippocrates and Galen proposed that our health and personality are dependent on the balance of four bodily fluids (i.e., yellow bile, black bile, blood, and phlegm), and Freud theorized that personality develops from libidinal energy that navigates through the body to target locations. Although the specifics of these approaches have been largely abandoned, the focus on finding a biological basis to personality has not. In recent years, researchers have added to our understanding of personality by integrating findings from affective neuroscience and neurobiology (e.g., Canli, 2006). And, just as functional magnetic resonance imaging (fMRI) technologies have allowed researchers the opportunity to peer inside the working brain, the emergence of non-invasive hormone sampling techniques has allowed researchers to incorporate hormones in their studies with human participants.

Hormones are generally produced in the Golgi cells of glands and travel through the circulatory system to specific target receptors. They differ from the other most common class of chemical messengers in the body, neurotransmitters, in that the effects that they produce take much longer to occur because of the time it takes for them to travel. This time can take anywhere from seconds to hours as opposed to the millisec...

Table of contents

• Cover
• Half Title
• Editorial Board
• Title Page
• Copyright Page
• Contents
• List of Figures
• List of Tables
• Notes on the Editor and Contributors
• Part I Biological Origins of Personality and Individual Differences
• 1 Hormonal Influences on Personality and Individual Differences
• 2 Molecular Genetic Studies of Human Temperament
• 3 Digit Ratio and Personality and Individual Differences
• 4 Morningness–Eveningness and Sociosexuality from a Life History Perspective
• 5 Toward the Molecular Basis of Personality
• Part II Developmental Origins of Personality and Individual Differences
• 6 Individual Differences in Personal Narrative: Coherence, Autobiographical Reasoning and Meaning Making
• 7 Developmental Profiles of Individuals with Psychopathic Traits: The Good, the Bad and the Snake
• 8 Generational Changes in Self-Esteem and Narcissism
• 9 The Role of the Family in Personality Development
• 10 The Role of Peers in Personality Development
• 11 Personality Development in Adolescence and Young Adulthood
• 12 The Development of Evolutionarily Adaptive Individual Differences: Children as Active Participants in Their Current and Future Survival
• 13 Cross-Situational Consistency, Variability and the Behavioral Signature
• 14 Transactions of Personality and the Social Environment During Development
• 15 Personality Development in Adulthood
• 16 Moral Character: Current Insights and Future Directions
• Part III Environmental Origins of Personality and Individual Differences
• 17 Cross-Cultural Perspectives on Personality and Individual Differences
• 18 Threat of Infectious Disease
• 19 Sex Ratio Influences on Personality and Individual Differences
• 20 Individualism and Collectivism
• 21 Exploring Potential Causes of Individual Differences in the Expression of Neonatal Imitation
• 22 Individual Differences and Romantic Relationships: Bidirectional Influences on Self and Relational Processes
• 23 The Gender Similarities Hypothesis
• 24 Positive Personality Change Following Adversity
• 25 Self-Sacrifice for a Cause: A Review and an Integrative Model
• Index