This post accompanies my other post about why I think it’s better to aim for depth over breadth in IB Psychology.

What is depth?

Depth refers to studying a topic by looking at only one or two examples.


  • Studying “Biases in thinking and decision making” by focusing only one on example, e.g., confirmation bias.
  • Studying the effects of one hormone on one behaviour (e.g. cortisol on memory).
  • Studying the effects of one cultural dimension on behaviour.

What is breadth?

Breadth refers to looking at multiple examples and/or a wide range of research relevant to a topic.


  • Studying three different types of biases in thinking and decision making, e.g. confirmation bias, optimism bias and illusory correlations.
  • Studying three effects of one hormone (e.g. testosterone’s role in aggression, competition and attraction) or the effects of three hormones.

The IB Psychology course has been designed to encourage breadth or depth, but I think it’s always better to aim for depth.