It is gratifying and significant that so many scientists from diverse fields are arguing in-depth regarding a particularly complex set of social emotions in a non-human animal. Emotions play a fundamental role in decision making and information processing. Neuroimaging is important in understanding the cognitive and emotional worlds of non-human animals and can help measure covert emotions lacking clear behavioral correlates. Various experimental approaches could clarify the relative importance of attachment and aggression in jealousy and whether the phenomenon we measured is more akin to human envy or jealousy. Reverse inference from amygdala activation is probably justified because behavior is “degenerate”: there are fewer behavioral programs than brain states that give rise to them. Individual differences are also important
