for a special affinity and link to the past?

[bosunyum]

The following sentences are from the story "Beyond rivalry" which is about the relationship betwen sibilings. And i have several questions about the meaning.

1. Brothers and sisters turn back to each other for a special affinity and link to the past. --what does the underlined sentence mean? espcially how can i translate the work affinity? ( liking or relationship?)

2.Many would call more often to check in and see how the other was doing. Here what does it mean by check in?

3. Women were more likely to cite emotional motivations such as feeling of empathy and security (towards their siblings)--what does this sentence mean? can you phraphrase it for me?

4.siblings seems to evoke positive feelings based on the [B]images [/

5. Lastly, what is the meaning of performing favors?

[Donbelid]

1) Empathy and recalling childhood days.
2) to check in = to make routine contact with a person
3) It was more probable that women (rather than men) talk about their emotional feelings like empathy and the feeling of security towards their brothers and sisters.
4) It seems that positivive feelings among brothers and sister emerge by the images... (I believe the rest of the sentence is ignored)
5) showing kindness