Phrenology was the bizarre belief that one could determine personality and intellectual ability by examination of the contours of the skull. The idea had a remarkable hold on the public imagination in the nineteenth century, but eventually died out, mainly because it had no plausible biological basis and because it was used to give a bogus scientific credibility to racism. The contemporary equivalent of phrenology is functional Magnetic Resonance Imaging (fMRI). “Functional” MRI differs from standard MRI scanning by mapping the differential rate of oxygen consumption in different parts of the brain: this is thought to measure metabolic, and hence, neuronal activity. Functional MRI scans display impressive colour changes which reflect these differences in oxygen consumption. If an area of the brain “lights up” during a specific activity, it is assumed that this activity “takes place” in that location. Academic psychologists, who had hitherto been low in the pecking order of neuroscience, thought fMRI might give them scientific credibility, and even recognition by the general public.
The sociologist Scott Vrecko listed fMRI-based neurobiological accounts of altruism, borderline personality disorder, criminal behaviour, decision-making, fear, gut feelings, hope, impulsivity, judgement, love, motivation, neuroticism, problem gambling, racial bias, suicide, trust, violence, wisdom and zeal. “Neurobollocks”− as this new phrenology came to be labelled by its detractors − has infiltrated economics, criminology, theology, literary criticism, education, sociology and politics: the American writer Matthew Crawford described fMRI as “a fast-acting solvent of the critical faculties”. Many cautious, reticent neuroscientists, however, are painfully aware of its limitations. The neuroscientist David Poeppel observed that “we still don’t understand how the brain recognizes something as basic as a straight line”.