Suppose a researcher asks particpants to recall the age they started smoking
Participants are likely to overestimate or underestimate their answer
Leading to incorrect conclusions
People tend to evaluate events based on how recntly they feel they occurred, rather than logically counting the time that has passed.
See the full study here :
Shillington, A. M., Woodruff, S. I., Clapp, J. D., Reed, M. B., & Lemus, H. (2012). Self-reported age of onset and telescoping for cigarettes, alcohol, and marijuana: Across eight years of the national longitudinal survey of youth. Journal of child & adolescent substance abuse, 21(4), 333-348, https://doi.org/10.1080/1067828X.2012.710026