Marsh et al (2014)

Background

- Altruism: Acting prosocially to increase another's welfare regardless of any cost on the self

Psychopaths are individuals who demonstrate failure to empathise with others and thus prosocial behaviour

There is much research to support that the brains (structure specifically) of psychopaths are different from brains of the average person.

- Research (by Adriane Raine) has shown that psychopaths have reduced amygdala responses to fearful facial expressions as well as reduced amygdala volume

- If this is true, psychopaths are the opposite of "extraordinary altruists", who went beyond the altruistic limits of most people.

In this study, "extraordinary altruists" were those that donated a kidney to a stranger, despite the very plausible severe medical risks in the present and future

Aim

To investigate "extraordinary altruism"; if the amygdalas of "extraordinary altruists" might have observable differences from other amygdalas, in particular those of psychopaths

PPS

- 19 "extraordinary altruist" kidney donors (7 women; 12 men) recruited through local newspaper ads and electronic media

- 20 controls who matched the IQ, income, education, psychological history, and medication use.

Age ranged from 23 - 56.

The donations were made to strangers, not to family or friends

Procedure

3 stages:

1: Emotion recognition task in an fMRI

- PPS were shown faces showing one of 6 basic emotions (joy, anger, sadness, surprise, fear, disgust)

- Each emotion was shown at moderate or high intensity

- Total of 120 images (6 expressions x 2 intensities x 10 examples)

2: The PPS had an MRI scan taken to determine their brain structure

3: PPS took a psychopathy and an empathy test

Results

- Extraordinary altruists had greater right amygdala volume (left was the same compared to controls) - the right hemisphere of the amygdala is associated with negative emotion

- There was a faster reaction time in the right amygdala, recognising the negative emotions, than in the control group

Link back

- The study shows that there may be a biological (brain structure based) origin/basis for altruistic behaviour

Strengths

- Controls were matched in a very detailed manner to the PPS and therefore severe differences in amygdala due to other factors than those investigated is made unlikely

- Both genders used

- Method (fMRI and MRI) is free of any personal biases or self-responses the pps may have in other studies involving the investigation of prosocial behaviour - brain activity and structures are set in stone

Limitations

- Study is correlational = There was no manipulated IV, and the experiment was a quasi experiment and therefore no cause and effect relationship can be established

- Study does not suggest what the origin of the structural differences may be, or provide any way to aid in the promotion of prosocial behaviour in the majority of the population

- Small sample size; and not generalizable to the majority of the population as they are not "extraordinary altruists"