What causes some people to mistakenly think the given syllogism is valid?

The belief bias impacting reasoning is a well-documented phenomenon in cognitive psychology. When individuals are presented with syllogisms, their existing beliefs can unconsciously influence their evaluation of the argument's validity. This means that if the conclusion aligns with what they already believe to be true, they are more likely to consider the syllogism valid, regardless of its logical structure. Conversely, if the conclusion contradicts their beliefs, they may dismiss a valid syllogism as incorrect.

Belief bias highlights the interplay between logic and personal conviction, showing that reasoning can be swayed by prior knowledge or emotional investment in a particular conclusion. This cognitive bias leads to a misunderstanding of logical reasoning, as people may overlook formal rules of logic in favor of their subjective beliefs.