MIT neuroscientists published a study which provides evidence that a magnetic field applied to certain portions of the brain can impact morality judgements. If true, that seems to be a clear example of a magnet's noticeable effect on humans.
When we judge an action as morally right or wrong, we rely on our
capacity to infer the actor’s mental states (e.g., beliefs, intentions).
Here, we test the hypothesis that the right temporoparietal junction
(RTPJ), an area involved in mental state reasoning, is necessary for
making moral judgments. In two experiments, we used transcranial
magnetic stimulation (TMS) to disrupt neural activity in the RTPJ
transiently before moral judgment (experiment 1, ofﬂine stimulation) and during moral judgment (experiment 2, online stimulation).
In both experiments, TMS to the RTPJ led participants to rely less on
the actor’s mental states. A particularly striking effect occurred for
attempted harms (e.g., actors who intended but failed to do harm):
Relative to TMS to a control site, TMS to the RTPJ caused participants
to judge attempted harms as less morally forbidden and more
morally permissible. Thus, interfering with activity in the RTPJ disrupts the capacity to use mental states in moral judgment, especially
in the case of attempted harms.
—Disruption of the right temporoparietal junction with transcranial magnetic stimulation reduces the role of beliefs in moral judgments by Liane Young, Joan Albert Camprodon, Marc Hauser, Alvaro Pascual-Leone, and Rebecca Saxe