Abstract
An attitude is an evaluation of an entity (Eagly and Chaiken, 1993)—it is how much a person likes or dislikes something. Persuasion is the process of changing an attitude (Petty and Cacioppo, 1986). As scientists, our ideas are constrained by the humans who communicate them. Hovland, Janis, and Kelley (1953) organized research on attitudes and persuasion into the framework of “Who said what to whom.” Helen Fisher's book Why Him, Why Her? is constrained by the same principles of any other communication. This review will examine Fisher's book from the framework of Hovland et al.
The answer to “who” is the messenger, Helen Fisher, a professor of anthropology at Rutgers University. Fisher is an engaging writer who has attempted to disseminate the findings of her research on personality types and their relationship to human pair-bonding. Social psychology tells that most of the time “birds of a feather flock together” is more accurate than “opposites attract” in that human close relationships are more likely to last when the pair-bond participants have more in common. However, the commonalities in this sense are usually attitudes and demographic. Fisher presents a great deal of evidence that personality types function in a slightly different manner.
The answer to “what” is the message of the book. Why Him, Why Her? develops the idea of four basic personality types: Builder, Director, Explorer, and Negotiator. Builders are traditional and match up well with builders. Directors are competitive and match up well with negotiators, who are agreeable. Explorers are adventurous and match up well with other explorers. Thus, for builders and explorers, birds of a feather do flock together. For negotiators and directors, they do not. That is to say that negotiators and directors seek complementary personality types (these types are not “opposite” to each other). Fisher believes that each of the personality types is rooted in neurochemistry: explorers with high dopamine, builders with high serotonin, directors with high testosterone, and negotiators with high estrogen. No direct evidence linking these neurotransmitters and hormones to personality types was presented, but a case was made from existing behavioral research on the neurotransmitters and hormones.
The idea of the four personality types is based on a Chemistry.com survey of 30,000 participants to make the case for each of these types, using methods of correlation. Supporting biological research conducted by mostly other researchers is also discussed. The last portion of the book is dedicated to giving advice to men and women of each personality type to help them to better understand what each type means for future interactions with members of each type.
The answer to “whom” is a very wide audience. Fisher's book is informative for personality psychologists, social psychologists, clinical psychologists, counseling psychologists, anthropologists, and evolutionary psychologists, among others. In addition to presenting evidence for the personality types, Fisher also makes many interesting testable hypotheses, to be discussed later in this review.
The book is fascinating. It has used appropriate methods to establish the existence of the distinct and accurately interpreted four personality types. It also included an appropriate discussion of relevant biological studies, all of which were accurately summarized. The book promotes scientific inquiry and is appropriately written for a non-specialist audience. Much of the book is based on research directly relevant to answering the questions it poses and all of the questions are formed in a testable and falsifiable manner.
There are, however, three core criticisms that can be made. Given that Why Him, Why Her? was not written for an academic audience, there was no need to have addressed these issues in the book itself. However, the publication of the studies on which it is based and future academic publications regarding this work would benefit from addressing the three concerns outlined below.
First, the sample was much too large. Rarely do we (in psychology) use such large samples for correlational studies. The reason for this is many correlations that manifest are often spurious with such large sample sizes. Smaller samples with the same results provide better support for a theory when compared to a larger sample. The appropriateness is an issue of descriptive versus inferential. If the goal of the study is to just describe the Chemistry.com participants, the large sample size does a great job of it. However, if it is to generalize beyond this, the sample is insufficient. This leads to the second issue.
Second, the sample may suffer from self-selection. If inferential generalizations are to be made from the Chemistry.com sample, a substantial effort must be made to demonstrate that the sample used is representative of the mating population at large. This is an empirical question. For example, what if people of higher mate value are not represented at all in the sample? People who choose to use Chemistry.com may not be different from people who do not seek pair-bonding opportunities in this manner, but to generalize beyond the sample this question must be empirically answered. Are people who use Chemistry.com different from people who do not? Are Chemistry.com members evolutionary losers with a second chance afforded to them by science and technology? Are Chemistry.com members evolutionary winners with the savvy to use all mating opportunities afforded to them? The sample size here proves to be a strong point of the study if it is a diverse enough sample, but this question must be answered before we can believe that the four personality types generalize to people beyond the Chemistry.com sample.
Third, there is absolutely no neurological/biological evidence to support causal links in the theory outlined in the book. The author hasn't measured a drop of serotonin, testosterone, estrogen, oxytocin, etc. There is a circular logic, as if to say, “These hormones are associated with these characteristics, therefore if I find these characteristics, they must indicate these hormones.” Epigenetics are hardly so simple, as Fisher acknowledges. Data in support of the statements made by the author are testable. A study could be conducted in which the sample is also measured for levels of hormones, and this data could be included in the correlation analysis. A series of such simple studies would provide support for many of the author's statements regarding neurotransmitter and hormone levels of the personality types and offer a much stronger statement for the causal role of these chemicals in each of the personality types.
Much of the biological research was stated as fact when much of it should have been stated as, “_____ type behaves this way, other studies have shown that _____ is involved in these types of behavior, therefore I believe that _____ may be higher (or lower) in _____ type.” This would be preferable to the structure of logic in the communication often used in the book, which was essentially, “_____ type behaves this way because they have higher (or lower) levels of _____. Other studies confirm this.” None of the other biological studies (other than an imaging study) were examining the new personality types, particularly the neurochemical/personality type relationship.
It may in fact be the case that the author has established answers to these issues. Such answers should be clarified in the scientific articles that derive from this work, as other scientists will no doubt have the same questions.
Criticisms aside, Why Him, Why Her? is an excellent book. It provides very proximal answers and does not answer ultimate questions to which evolutionary psychology seeks answers. This is where the book can be used by evolutionary psychologists to test ideas derived from evolutionary theory regarding Fisher's pair-bonding ideas. Evolutionary psychology is the unifying framework through which ultimate predictions can be made regarding Fisher's untested (and tested) ideas postulated in the book. In addition to compelling, interesting evidence regarding the personality types, this book may prove to be influential for many years regarding the falsifiable predictions that are made about the association of hormones and neurotransmitters with the newly established concepts of the four distinct personality types. Why Him, Why Her? has the potential to inspire pair-bonding research derived from evolutionary theory for many years.