My main argument is rather simple. I challenge Grossmann's claim (target article, sect. 2, para. 1) that heightened fearfulness among young children is an adaptive trait in the context of the human cooperative caregiving system. I do not deny that human sensitivity to fear in others is an adaptive trait. Rather, I argue that, because humans are ultrasocial, the adaptive nature of human sensitivity to fear in others in the context of their joint caregiving mitigates sufficiently (or even completely neutralizes) the negative effects of maladaptive heightened fearfulness in human children. The function of heightened fearfulness is gaining attention rather than leading to being helped and protected.

Grossmann's main argument can be deconstructed in the following way:

1. (1) The experience of fear in light of a threat in animals leads to fight-or-flight (or avoid being detected) responses.

2. (2) (However,) humans have an additional “tend and befriend” response.

3. (3) Arguably, this response is the most effective response in the face of fear in ultrasocial species because (inter alia):

   1. (a) it allows for potential threats or uncertainties to be cooperatively managed and avoided, and

   2. (b) in the context of heightened fear, the approach response may be particularly beneficial for the youngest and most vulnerable members of the species (i.e., the heightened fear increases the effectiveness of “tending”).

   Conclusion: (Therefore,) heightened fearfulness and sensitivity to fear in others are adaptive, interconnected traits (they generate direct fitness and survival benefits).

I challenge premise 3b. This premise assumes that the function of heightened fear is to lead to being helped and protected (target article, sect. 3.2, para. 8) but, given that the fear is exaggerated, even when there is a need to respond, the intensity of the response will not be proportionate to the real need for help: That is because the fearfulness is exaggerated, the reaction will be exaggerated as well. Because exaggerated reactions require using unnecessary resources, this response would lead to resource depletion (individuals that really need help would not be helped) if it weren't the case that humans are ultrasocial and the social structure can afford to allocate unnecessary resources in these circumstances. Therefore, heightened fear in children seems to be a consequence of a lucky circumstance; specifically, the fact that humans live in intense cooperation.

In this context, then, heightened fearfulness is a flaw but, given the nature of human cooperation, it is not a debilitating flaw. The disposition is disadvantageous, that is, but human social cooperation is capable of sufficiently mitigating its negative effects. If this hypothesis is correct, then heightened fear does not lead to being helped; rather being surrounded by many alloparents capable of providing more attention leads to human children exhibiting heightened fear. The heightened fear is a mechanism of getting additional attention rather than seeking help: The more attention children get as a response to exhibiting fear, the stronger and more frequent their display of fear becomes.

The fact that a disposition, trait, or behaviour is not adaptive does not entail that it will disappear. The evolutionary processes may just need some time to deselect it. Also, some relevant historical circumstances may facilitate or tolerate it: As an example, consider the example of the so-called “nervous” or “fainting” goats (e.g., Lush, Reference Lush1930; White & Plaskett, Reference White and Plaskett1909). When “nervous” goats are suddenly surprised or startled, they become perfectly rigid. Typically, this condition lasts only 10–20 seconds but it is still not adaptive for these goats to freeze in the face of danger; because this is not a strategy for avoiding detection. Interestingly, farmers find this behaviour useful because the goats cannot jump over fences: They freeze if they try. What this means is that farmers gave a function to the goats' functionless, maladaptive disposition thereby transforming it into an adaptive disposition. Also, some pointer dogs exhibit sudden immobility in the presence of humans (Reese, Newton, & Angel, Reference Reese, Newton and Angel1982, p. 611). Unlike the above farmers, owners of these dogs do not find the behaviour useful but they do not see it as a reason not to have these dogs. The dogs' disposition is neither adaptive nor debilitating.

Similarly to the sudden immobility of these pointer dogs, many human traits and dispositions are not adaptive but human society is capable of mitigating, neutralizing, or simply tolerating their negative effects. My suggestion is that heightened fearfulness among infants and young children is a trait of this kind. Likewise, self-inflation bias does not seem to be adaptive but contemporary society tolerates it to an extent (see, Funkhouser, Reference Funkhouser2019, sect. 7) and many cases of self-deception are also not adaptive but are tolerated or facilitated by the relevant historic circumstances (see, Krstić, Reference Krstić2020).

In conclusion, the fearful ape hypothesis assumes that the function of heightened fearfulness is to lead to being helped and protected. This hypothesis sits uneasily with the fact that the degree of the response does not correspond to the degree of the real need for help (the fear is exaggerated). Thus, the function of this trait does not seem to be leading to being helped and protected; rather, getting attention may be the real function. According to the rival, nervous goat hypothesis, this trait is not adaptive but it still exists because humans are capable of developing a relevant response and the response is owed to our adaptive sensitivity to fear in others. Perhaps, one beneficial side-effect of this overall situation is that these infants grow up to become more caring and cooperative human beings in the long term but it does not follow that this is a function of heightened fearfulness.