Final answer:
The main drawback of self-report questionnaires in assessing personality is the tendency for individuals to answer in socially desirable ways, compromising the validity of the assessment. This bias can lead to responses that do not accurately reflect true personality traits.
Step-by-step explanation:
One drawback of the self-report questionnaire method of assessing personality is that people may answer the questions in a way that reflects how they want to be perceived, rather than how they truly are. This tendency to present oneself in a socially desirable light can compromise the validity of the personality assessment, as it may not accurately capture the individual's authentic personality traits. The influence of social desirability bias is particularly strong in situations where there are perceived benefits to being viewed in a certain way, such as during a job application process, leading to responses that are exaggerated, biased, or misleading. Additionally, relying on self-report can be time-consuming and captures what people think and believe but not necessarily how they behave in real life, which could limit the usefulness of the data collected for certain research purposes.