句子来自2014年专八改错，前文介绍了“二语习得”这个新兴的领域主要有哪些热门的研究话题。我有两处疑惑：

1.句子：From a review of the literature of the field it is clear that all the approaches adopted to study the phenomena of SLA so far have one thing in common: The perspective adopted to view the acquiring of an additional language is that of an individual attempting to do so.

疑惑：请问黑体句里从句中的an individual指的是谁，为什么？to do so，so指的是什么？

2.句子：Whether one labels it "learning" or "acquiring" an additional language, it is an individual accomplishment and what is under focus is the cognitive, psychological, and institutional status of an individual.

疑惑：请问部分的institutional怎么理解？

附上原文（已将错误改正）：

There is widespread consensus among scholars that second language acquisition(SLA) emerged as a distinct field of research from the late 1950s to early 1960s.

There is also a high level of agreement that the following questions have captured the most attention of researchers in this area:

1. Is is possible to acquire an additional language in the same sense as one acquires a first language?

2. What is the explanation for the fact that adults have more difficulty in acquiring additional languages than children have?

3. What motivates people to acquire additional language?

4. What is the role of language teaching in the acquisition of an additional language?

5. What sociocultural factors, if any, are relevant in studying the learning of additional language?

From a review of the literature of the field it is clear that all the approaches adopted to study the phenomena of SLA so far have one thing in common: The perspective adopted to view the acquiring of an additional language is that of an individual attempting to do so. Whether one labels it "learning" or "acquiring" an additional language, it is an individual accomplishment and what is under focus is the cognitive, psychological, and institutional status of an individual. That is, the spotlight is on what mental capabilities are involved, what psychological factors play a role in the learning or acquisition, and whether the target language is learnt in the classroom or acquired through social interaction with native speakers.