Question: I (male) recently started a very corporate job. I'm a recent grad so I'm younger than most of my coworkers, most of which are married/have kids. I get along pretty well with all of them.

There is another recent hire, also a recent grad, who is the exception to this. He hasn't said anything hostile or derisive to me, but his behavior specifically toward me is kind of *cold*.

He gets perceptibly annoyed when I try to join group conversations in which he is involved. He never asks for any elaboration when I tell stories (but he does when others regale him). He seems to avoid asking me for help when he goes around asking some coworkers when he's stuck, even on things he knows me to be good at.

I haven't the slightest idea what I've done to make him act this way toward me. I want to ask him to find out, but I don't want to exacerbate the tension. I think it would be a little melodramatic to approach my boss about this.

**How can I bring this up with my coworker?**

Answer: 
Your coworker's behavior sounds hurtful. Unfortunately, you will encounter many coworkers over the course of your career that will be standoffish or cold in their interactions with you. This is not necessarily because of anything that you did to them. It could be for a variety of reasons: they are not interested in making friends at work, they are narcissistic, they feel threatened by your presence, or yes, possibly because there is something about you that they don't like, among other reasons. While this is challenging, there is nothing that you can do to prevent it.

In your time at work, you will need to establish boundaries with your coworkers that may be different from the boundaries that you establish in social settings. However, just like in a social setting, spend time with coworkers that make you feel positive and confident, even if they are older than you. When you have to interact with him, keep the conversational professional. If you find that your office requires a lot of social interaction (for example, your team eats lunch together every day), and you are required to interact with him in this setting, then consider asking him questions about himself in order to get to know him better. However, it is generally advisable to avoid talking about very personal or contentious topics with your coworkers unless you have been working with them for a long time, and they have become your "real" friends.

At work, your first priority is to do the best that you can in executing your tasks. If you minimize your social interactions with him, maintain a professional demeanor, and complete your tasks well, then you can build a positive "coworker" relationship with him, even if the two of you are not compatible as "real" friends.

And yes, if this coworker is exhibiting hostile behavior towards you, rather than just a cold demeanor, document it to the best of your ability. This is very useful if you feel that you do need to escalate.
Just don't make a big deal of it, try to "get over it" emotionally so that his behaviour does not hurt you any more. Try to perceive it not as your problem but his problem: you are OK, but *he* seems to feel bad about interracting with you. Then you can simply approach him and ask him (at some suitable time, or perhaps you can invite him to have a glass of beer with you, or whatever): hey, you seem not to be very comfortable with me, what's the problem? What can I do to help you? Am I doing something that annoys you? Be generous and candid. If he just shows irrational hostility, scorn or the like, just pity him, withdraw and stop bothering about it - he clearly is not the kind of person whose opinion on you should matter to you. If he points to some particular reason why he dislikes you that can be fixed, you may promise to try to work on it. If it can't be (reasonably) fixed, at least try to make him aware that you understand his feelings. If he says he simply does not like you and refuses to give any particular reason, you may say something like "Oh, that's life, I am glad it is not my fault, please let me know if you can think of something I can do so that you feel better; meanwhile let's take it as a fact and try to get along with each other as well as we can, shall we?" Avoid being judgemental, avoid focusing on your own emotions (best leave them out of the issue entirely), don't demand an instant solution, be prepared to acknowledge your own fault if there is one , but don't be defensive, and above all, don't scrounge for respect (or anything at all).
Additionally, you can ask your other coworkers why they think the guy has problem with you.