Weaknesses

• Case study method is unscientific - little Hans

  -Can't be generalise theories from small samples and mentally ill people so not representative of the wider population.

  -Issues of researcher bias and lack of objectivity in interpretating data.
• Untestable concepts

  -ID/superego, defence mechanisms operate in unconscious.

  -Difficult to test empirically using scientific methods.

  -Theories can't be replicated to be falsified which is a key science feature.
• Psychic determinism 


  -Free will as an illusion.

  -Behaviour is determined at an unconscious level between ID and superego and innate drives.

  -No accidents even the slip of the tongue is determined by the unconscious. Adult behaviour determined by childhood experiences.