The Psychologist’s Green Thumb

The ‘psychologist’s green thumb’ refers to the argument that an experimenter needs an indeterminate set of skills to successfully replicate an effect. This argument is sometimes invoked by psychological researchers to explain away failures of independent replication attempts of their work. In this paper, I assess the psychologist’s green thumb as a candidate explanation for individual replication failure and argue that it is potentially costly for psychology as a field. I also present other, more likely reasons for these replication failures. I conclude that appealing to a psychologist’s green thumb is not a convincing explanation for replication failure.