Explanations of impulse control disorders — practice questions

AO1 — Biological explanation:

• Prefrontal cortex regulates executive control and inhibits inappropriate behaviour.
• Dysfunction (injury, developmental deficit) → reduced behavioural inhibition.
• Low serotonin linked to impulsivity — supported by some response to SSRIs in kleptomania/pyromania.

AO1 — Learning theory explanation:

• Tension–release cycle maintained by operant conditioning.
• Impulsive act → relief/pleasure (negative reinforcement) → urge strengthened over repetitions.
• Antecedents (stress, boredom) become cues triggering impulse via classical conditioning.

AO3 — Evaluation of biological reductionism:

• Strengths: Neuroimaging and pharmacology offer objective evidence; guides drug treatment.
• Limitations: Reductionist — ignores social learning, poverty, peer influence; not all impulsive individuals show brain abnormalities.
• Incomplete causality: Biology may correlate with rather than cause behaviour — chicken-and-egg problem.
• Free will vs determinism: Biological account suggests hard determinism — problematic for legal responsibility.

Judgement: Most complete account is interactionist — biological vulnerability lowers inhibition threshold while learning maintains the urge–relief habit.

(a) Identification [1 mark]

The schedule of reinforcement is a Variable Ratio (VR) schedule. This is because reinforcement (a win) is delivered after an unpredictable number of responses (plays).

(b) Calculation [2 marks]

• Step 1: Identify total responses and total reinforcements.

  • Total responses (plays) = 150
  • Total reinforcements (wins) = 6

• Step 2: Calculate the average ratio.

  • Formula: Average Ratio = Total Responses / Total Reinforcements
  • Calculation: 150 / 6 = 25

• Answer: The schedule is, on average, a VR-25 schedule. Reinforcement occurs on average every 25 plays. [1 mark for correct working, 1 mark for correct answer]

(c) Explanation [3 marks]

• High Rate of Responding: The unpredictability of the reward encourages a high and steady rate of responding. The gambler knows that a win is possible on any given play, which motivates them to keep playing quickly. [1 mark]

• Resistance to Extinction: VR schedules produce behaviour that is highly resistant to extinction. Because the gambler is used to long periods without reinforcement, they will continue to play even during a losing streak, believing a win is 'due' soon. [1 mark]

• Dopamine and Anticipation: The anticipation of a potential win, fueled by the unpredictability, is itself rewarding and triggers dopamine release in the brain's reward pathway. This creates a powerful 'buzz' that reinforces the act of playing, even more than the occasional small win does. [1 mark]