Final answer:
The non-adaptive fear response among the options given is (d) fear of rejection leading to risky behaviors. This is because adaptive fear is meant to protect us, and engaging in risky behaviors can jeopardize safety, contrasting with other fear responses which historically aided survival.
Step-by-step explanation:
Fear responses can be adaptive, meaning they help in coping with threats or challenges. Adaptive fear responses include physiological and psychological changes that prepare an organism to confront or evade danger, an evolutionary trait linked to survival. When discussing adaptive fear responses, it's important to differentiate between responses that are beneficial for survival and those that might lead to negative outcomes in modern contexts.
Among the examples given, the item (d) fear of rejection can lead us to engage in risky behaviors is the one that is not adaptive. This is because the adaptive function of fear is to protect and enhance survival. Engaging in risky behaviors in response to fear of rejection is counterproductive to this aim, potentially endangering well-being rather than protecting it.
On the other hand, the other examples provided—(a) fear preparing our body to flee from danger, (b) fear binding people together, and (c) fear of injury protecting us from harm—reflect the traditional utility of the fight-or-flight response. These responses are deeply engrained in our nervous system and have historically increased an individual's chances of survival. However, the frequent activation of this response to psychological or non-life-threatening stimuli in modern times can lead to health issues such as heart disease and a weakened immune system.