The fight or flight response

What is the fight or flight response?

The flight or flight response is the body’s automatic physiological reaction to a perceived threat or stressor.

What is the amygdala?

Part of limbic system, detects emotional significance of stimuli, e.g. fear of threat. - associates sensory signals with emotions.

What is the hypothalamus?

Acts as the command centre, coordinating a response.

Communicates with the rest of the body via the autonomic nervous system. - sympathetic nervous system branch.

Initiates 2 pathways; one for acute stress and one for chronic stress.

How does the body response to acute stressors?

The sympathetic nervous system is triggered by the hypothalamus, and it prepares the body for the rapid action necessary. It sends a signal through the body to the adrenal medulla, which responds by releasing the hormones adrenaline and noradrenaline.

Adrenaline; triggers physiological changes.

After the threat has passed, the parasympathetic nervous system dampens down the stress response; digestion resumes, breathing rate lower, heart rate lowers.

What are the Physiological changes caused by adrenaline?

Heart rate increases → pushes more blood to muscles heart and other vital organs. + blood pressure increases.

Breathing rate increases → More oxygen is taken in

Triggers the release of glucose and fats into the bloodstream, supplying energy to the parts of the body associated with the fight or flight response.

What is the body’s response to chronic stressors?

HPA axis;

Hypothalamus, detects ongoing stress and releases the chemical messenger/hormone (CRH) into the bloodstream.

It arrives at the anterior pituitary gland and triggers the release of ACTH, which is sent to its target site in the adrenal gland.

The adrenal cortex, triggered by ACTH, releases stress related hormones such as cortisol, which has positive effects such as, bursts of energy, lower pain sensitivity, and negative effects such as, impaired cognitive performance, lowered immune response.

Receptors in the hypothalamus and pituitary gland monitor cortisol levels, if these rise above normal, they initiate a reduction in CRH and ACTH, thus bringing cortisol levels back to normal -feedback.

Evaluate the fight or flight response

Limitation

Gender bias

Gender bias - Taylor eat al 2002

Point; Findings may not fully apply to females.

Evidence; Taylor et al, suggests that females are more likely to adopt a tend and befriend response, seek social support and protect their offspring rather than fighting or fleeing.

Explain: This behaviour is thought to be due to the role of oxytocin - hormone that promotes bonding and reduces anxiety which may be more influential in females due to oestrogen.

Link: therefore fight or flight may reflect a beta bias in psychology, as it is largely based on male research and ignores possible gender differences in stress response.

Evaluate the fight or flight response

Limitation

Oversimplified

Point; Doesn’t fully capture the full range of human responses to threat

Evidence: Gray 1988 argued that the first response to danger is not fight or flight but rather freeze. Involved a heightened alertness and allows the individual to assess the situation more carefully before acting.

Explain: Reaction can be more adaptive as it gives people more time to gather information and make strategic decisions.

Link: Traditional fight or flight may lack completeness.

Evaluate the fight or flight response

Limitation

Biological and cognitive factors

Point: Theory mainly focuses on biological differences and ignore individual differences in cognition.

Evidence: Not everyone reacts the same, past experiences, personality, cognitive appraisal (hoe the threat is perceived) all affect the response.

Explain: One person might perceive a situation as threatening and trigger a fight or flight, while another might see it as manageable and remain calm.

Link: Suggests that the model is too biologically deterministic and doesn’t fully account for the complexity of human behaviour.

Evaluate the fight or flight response

Strength

Scientific

Point: The fight or flight response has high biological credibility

Evidence: The role of the amygdala, hypothalamus and hormones have all been demonstrated through the use of brain imaging, blood tests and animal studies.

Explain: Studies consistently show the activation of the SNS and hormones released during stress, supporting the idea of a biological basis.

Link: Fight or flight is a valid explanation of the body’s physiological reaction to stress, supported by objective, measurable research.