Philosophy of Psychology. Lisa Bortolotti
well as empirical inputs.
Suppose that you are interested in whether humans have some property X, such as the property of being rational or the property of being altruistic. To answer this, you need to investigate two sets of questions: (1) ‘What does it mean to have X?’, ‘What is necessary for a person to have X?’, and ‘What is sufficient for a person to have X?’; and (2) ‘Do humans satisfy a sufficient condition for having X?’, ‘Do humans fail to satisfy a necessary condition for having X?’, and ‘What do empirical studies say about these issues?’ Let us call the former the ‘philosophical questions’ about X, and the latter the ‘psychological questions’ about X.
Addressing the philosophical questions requires the articulation and justification of certain (controversial) claims, such as ‘being rational’ means reasoning in accordance with the rules of logic and mathematics, or ‘being altruistic’ means being motivated to increase somebody else’s well-being for its own sake. Addressing the psychological questions requires setting up laboratory experiments and observations in the wild, where human behaviour is assessed on the basis of the criteria for rationality or altruism, such as measuring how many people out of 100 commit a logical fallacy in a simple test or how many people out of 100 act in a selfless way given the chance.
The reason you can’t just let philosophers do what they do is that although a purely philosophical investigation is useful for addressing the philosophical questions, it does not say much about the psychological questions. For instance, a philosophical argument does not say anything about whether as a matter of fact humans can be motivated to increase somebody else’s well-being for its own sake. In contrast, the reason you can’t just let psychologists do what they do is that although a purely psychological investigation is useful for addressing the psychological questions, it does not say much about the philosophical questions. For example, a psychological experiment does not say anything about whether ‘rationality’ should be regarded as the capacity for reasoning in accordance with the rules of logic and mathematics.
Let us think about a further example (which we discuss in detail in Chapter 6). Suppose that you want to know whether humans have free will and responsibility, according to relevant psychological findings. To know this, you need to investigate both the philosophical and the psychological questions: (1) ‘What does it mean to have free will?’, ‘What is necessary for a person to have free will?’, ‘What is sufficient for a person to have free will?’; (2) ‘Do humans satisfy a sufficient condition for having free will?’, ‘Or, do humans fail to satisfy a necessary condition for having free will?’, ‘What do empirical studies say about these issues?’
A purely philosophical investigation can address the philosophical questions, but not the psychological questions. For example, one might argue, for some philosophical reasons, that it is necessary for person A to have free will that A’s conscious mental states and processes play some significant causal role in producing or controlling A’s behaviour. This is certainly a possible answer to a philosophical question, but we need to know more to ascertain whether humans have free will. In particular, the psychological questions have not been answered yet. It is still unclear whether, according to relevant empirical studies, conscious states and processes in human cognition play the right kind of causal roles. As we shall see in Chapter 6, this is the topic of a recent interdisciplinary debate on free will.
A purely psychological investigation can address the psychological questions, but not the philosophical questions. For example, psychological studies might suggest that Elsa’s discriminatory behaviour is generated by her implicit biases, which can only be detected by psychological tests. Elsa is not introspectively aware of her biases. This is certainly an interesting finding, but we need to know more to judge whether she is responsible for her discriminatory behaviour. In particular, the philosophical questions have not yet been addressed. It is still unclear whether Elsa’s lack of introspective awareness of her implicit biases is incompatible with her being responsible for her discriminatory behaviour. As we shall see in Chapter 6, this is the topic of a recent discussion about whether people are responsible for their implicit biases.
Evaluating Psychological Studies
This book focuses on implicational philosophy of psychology, investigating the implications of some particular psychological studies. Before getting into our main discussions, we would like to mention three factors that are relevant in the context of evaluating psychological studies and their implications: replication, research participants, and ecological validity.
Replication
Psychological studies, just like other scientific studies, need to be replicated in order to be credible. It is possible that some interesting results fail to be replicated. In fact, psychology, social psychology in particular, is now facing the so-called ‘replication crisis’ (e.g., Earp & Trafimow 2015): the replicability of social psychological studies, including some famous ones, seems to be remarkably low.
A recent controversy, for example, is about a series of studies of priming effects by John Bargh and colleagues. Priming effects are the unconscious effects that the exposure to a stimulus has on the responses to subsequent stimuli. One famous study (Bargh, Chen, & Burrows 1996, which has over 5,500 citations on Google Scholar as of October 2020) reports the surprising result that the participants who had completed the simple task of making a sentence out of some given words, including words related to stereotypes of the elderly (e.g., ‘grey’, ‘wise’, or ‘wrinkle’), walked away more slowly than other participants who had completed the same task without elderly-related words. However, several researchers (e.g., Doyen et al. 2012) reported their failure to replicate the elderly stereotype study and suggested that the popularity of priming studies by Bargh and colleagues is disproportional to their scientific credibility. Daniel Kahneman, who had once mentioned the elderly stereotype study in his best-selling book Thinking, Fast and Slow (2011), admitted that he had ‘placed too much faith in underpowered studies’ in response to a blog post on the controversy (Schimmack, Heene, & Kesavan 2017).
The problem is compounded by the fact that replication failure tends not to be reported in journals (unless, just like in the case of priming studies by Bargh and colleagues, a serious controversy arises). Paul Bloom says that when the project of replicating a study turns out to be unsuccessful, ‘[u]sually, the project is just abandoned, though sometimes the word gets out in an informal way – in seminars, lab meetings, conferences – that some findings are vaporware (“Oh, nobody can replicate that one”)’ and ‘[m]any psychologists now have an attitude that if a finding seems really implausible, just wait a while and it will go away’ (Bloom 2017, 224).
We do not necessarily endorse radical pessimism about social psychology; after all, many important studies have been replicated. But, as a general rule, replication should always be kept in mind when evaluating psychological studies, and perhaps some extra care is needed when evaluating studies in social psychology with surprising results.
Replication really matters, but what about the observations of rare conditions about which we cannot expect statistical analysis of data or replication? Despite the lack of statistical analysis or replication, the study of some unusual behaviours can be informative and can help us to understand how the mind works. In the book Phantoms in the Brain, V. S. Ramachandran defends the usefulness of observing rare cases as opposed to the statistical study of normal individuals:
[I]n neurology, most of the major discoveries that have withstood the test of time were, in fact, based initially on single studies and demonstrations. More was learned about memory from a few days of studying a patient called H.M. than was gleaned from previous decades of research averaging data on many subjects. The same thing can be said about hemispheric specialization (organization of the brain into a left brain and a right brain, which are specialized for different functions)