[問題] Longman minitest-2 (reading)

[jojoba]

請問各位大大 以下這題閱讀題:
from Longman minitest-2

A considetable body of research has demonstrated a correlation between birth order and aspects such as temperament and behavior, and some psychologists believe that birth order significantly affects the development of personality. Psychologist Afred Adler was a pioneer in the study of the relationship between birth order and personality. A key point in his research and in the hypothesis that he developed based on it was that it was not the actual numerical birth position that affected personality; instead, it was the similar responses in large numbers of families to children in specific birth order...

請問以下兩個it各是指稱什麼?

[micki]

下次發文 請把出處放在標題上

請盡量標明清楚 這樣版工以後要整理 或是其他朋友要搜尋也會比較方便
(書名/chapter/ question#, something like this)