Passage 1Questions to 5 are based on thefollowing passage.Many studies suggest. thatour personalities remain fairly stable, even over the course of decades. Yetsmall but long-running study finds that traits related to dependability differgreatly between adolescence and late life The findings raise new questions andhighlight the challenges in trying to track a person's defining characteristicsover many years.In the new research,published in December 2016 in Psychology and Aging, researchers in the U.K.reached out to a group of 635 77-year-olds from Scotland who had taken part ina study when they were 14. Back then, their teachers had rated them on sixpersonality characteristics related to dependability:sef- confidence,perseverance(坚定), mood stability, conscientiousness(认真),originality and desire to be better than others.Some 60 years later a total of174 participants from the original study rated themselves on the same sixtraits and had a close friend or relative rate them as well.Lead author lan Deary, apsychologist at the University of Edinburgh, expected, based on earlierfindings, that dependability scores might remain stable over time. In fact, heand his colleagues found no relation between ratings for dependability-relatedtraits over the 63-year span studied. (Deary emphasizes that his findings applyonly to these six traits-not overall personality.)One of the study's strengthsis that it covers such a long period, but this characteristic also makes theresearch challenging. Nate Hudson, a social psychologist at Michigan StateUniversity who was not involved in the study, points out that the lack ofpersonality stability could be the result of having different people rate theparticipants. Ideally, the same person would rate a subject's personality atboth time points when assessments were made.In decades-spanning studies,many subjects go missing, die or choose not to participate in follow-upassessments. Deary and his colleagues had only 174 of the originalparticipants, a number that makes it tough to find subtle but real,correlations in sets of data. "It is difficult to know from their studyalone whether there is truly zero stability in personality from age 14 to77," Hudson says. “Deary's work moves the field forward-but more research is needed toget full picture of how personality evolves throughout a lifetime.”How many years does Deary's research cover?