A large part of a person's cognitive and interpretive process is formed unconsciously. In some cases, even when decision-making is conscious, a person's thinking and decision-making are influenced by the unconscious process that dominates their mind, and it is at this stage that cognitive biases occur.
This research, using a Descriptive-Analytical method and direct findings from psychology in law, in response to how cognitive biases affect judges' judgments in terms of establishing causation, finds that the uncertainty of the legal system in the issue of causation and the legal doctrine's reference to custom to determine causation, have caused judges to use tools such as expert theory to establish custom and to make decisions on the issue of attributing responsibility by assuming themselves as an average and ordinary member of society; which causes the emergence and impact of cognitive biases. Although judges would not be able to render judgments without cognitive biases, and such phenomena, similar to the process of dreaming, occur at an unconscious level and are not subject to control, awareness of these biases may, to some extent, help mitigate their adverse effects on judicial decision-making.