Clarity of thought, clarity of language


Clarity of language leads to clarity of thought: this is the lesson of apply mathematics and logic to science. But even when we don’t have those tools, we can be careful about the words that we use when describing behavior and the brain. Words can be ambiguous, can mean different things to different people, or just plain misused Here is a list of 50 terms not to use. Here are some that I like:

(7) Chemical imbalance. Thanks in part to the success of direct-to-consumer marketing campaigns by drug companies, the notion that major depression and allied disorders are caused by a “chemical imbalance” of neurotransmitters, such as serotonin and norepinephrine, has become a virtual truism in the eyes of the public

(16) Love molecule. Over 6000 websites have dubbed the hormone oxytocin the “love molecule” (e.g., Morse, 2011). Others have named it the “trust molecule” (Dvorsky, 2012), “cuddle hormone” (Griffiths, 2014), or “moral molecule” (Zak, 2013). Nevertheless, data derived from controlled studies imply that all of these appellations are woefully simplistic (Wong, 2012; Jarrett, 2015; Shen, 2015). Most evidence suggests that oxytocin renders individuals more sensitive to social information (Stix, 2014), both positive and negative.

(19) No difference between groups. Many researchers, after reporting a group difference that does not attain conventional levels of statistical significance, will go on to state that “there was no difference between groups.” Similarly, many authors will report that a non-significant correlation between two variables means that “there was no association between the variables.” But a failure to reject the null hypothesis does not mean that the null hypothesis, strictly speaking, has been confirmed.

(27) The scientific method. Many science textbooks, including those in psychology, present science as a monolithic “method.” Most often, they describe this method as a hypothetical-deductive recipe, in which scientists begin with an overarching theory, deduce hypotheses (predictions) from that theory, test these hypotheses, and examine the fit between data and theory. If the data are inconsistent with the theory, the theory is modified or abandoned. It’s a nice story, but it rarely works this way

(35) Comorbidity. This term, which has become ubiquitous in publications on the relations between two or more mental disorders (appearing in approximately 444,000 citations in Google Scholar), refers to the overlap between two diagnoses, such as major depression and generalized anxiety disorder…Nevertheless, “comorbidity” can mean two quite different things. It can refer to either the (a) covariation (or correlation) between two diagnoseswithin a sample or the population or (b) co-occurrence between two diagnoses within an individual

(45) Scientific proof. The concepts of “proof” and “confirmation” are incompatible with science, which by its very nature is provisional and self-correcting (McComas, 1996). Hence, it is understandable whyPopper (1959) preferred the term “corroboration” to “confirmation,” as all theories can in principle be overturned by new evidence.


And some quibbles –

(4) Brain region X lights up. Many authors in the popular and academic literatures use such phrases as “brain area X lit up following manipulation Y”…Hence, from a functional perspective, these areas may be being “lit down” rather than “lit up.”

I will actually go to bat for “brain region X lights up”, despite its uninformed use in the popular press. Despite the fact that to a professional audience it sounds amateurish, it has a clear meaning in terms of the delta in brain oxidation levels.

(9) Genetically determined. Few if any psychological capacities are genetically “determined”; at most, they are genetically influenced. Even schizophrenia, which is among the most heritable of all mental disorders, appears to have a heritability of between 70 and 90% as estimated by twin designs

I thought that we had all agreed that nothing is 100% genetic, and genetically determined was equivalent to saying genetics have a “strong” impact on some behavior.

(18) Neural signature. One group of authors, after observing that compliance with social norms was associated with activations in certain brain regions (lateral orbitofrontal cortex and right dorsolateral cortex), referred to the “neural signature” of social norm compliance…Nevertheless, identifying a genuine neural signature would necessitate the discovery of a specific pattern of brain responses that possesses nearly perfect sensitivity and specificity for a given condition or other phenotype.

Is this the meaning of neural signature? I would never have used neural signature in this way. To me, a neural signature is a response that contains information about some stimulus or behavior.

(47) Empirical data. “Empirical” means based on observation or experience. As a consequence, with the possible exception of information derived from archival sources, all psychological data are empirical (what would “non-empirical” psychological data look like?).

Data from models is not empirical…

Before using a word, there are many things you must take into account: your audience, the way other words constrain the meaning of the chosen word, and so on. Even if I disagree on the meaning of, say, ‘neural signature’ I would not use it because it has such a multiplicity of meanings! Academic writing should always define its terms clearly and carefully; but lay writing must be equally careful not to allow the read to imply things that are not there. Be careful.


Lilienfeld SO, & et al (2015). Fifty psychological and psychiatric terms to avoid: a list of inaccurate, misleading, misused, ambiguous, and logically confused words and phrases
Frontiers in Psychology

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