Inhibition of the right dlPFC by theta burst stimulation does not alter sustainable decision-making.

Intergenerational sustainability is probably humankind's most pressing challenge, exacerbated by the fact that the present generation has to incur costs in order to benefit future generations. However, people often fail to restrict their consumption, despite reporting strong pro-environmental attitudes. Recent theorising sees self-control processes as key component of sustainable decision-making and correlational studies support this view, yet causal evidence is lacking. Using TMS, we here disrupted an area known to be involved in self-control processes, the right dorsolateral prefrontal cortex (dlPFC), to provide causal evidence as to whether diminished self-control leads to less intergenerational sustainability. Participants then engaged in a behavioural economic paradigm to measure sustainable decision-making towards the next generation. This adequately powered study could not find an effect of inhibiting the right dlPFC on intergenerational sustainability. This result holds when controlling for a number of relevant covariates like gender, trait self-control, pro-environmental attitudes, or cortical thickness at the stimulation site. We seek to explain this result methodologically and theoretically, and speculate about other brain areas that could be more strongly related to intergenerational sustainability, e.g. the mentalising network.