It's not possible to like or dislike people uniformly. There are people with whom we share warmth and liking. And there are those with whom there's a coldness that can't be removed. In many cases, our interactions with people are so shallow that it doesn't matter if we let them go out of our life because we didn't enjoy our first few interactions with them. This is not affordable in some cases, in particular when it involves a friend, a colleague or someone within the family.
At work, developing an overall negative emotional chemistry with a co-worker can have very detrimental effect on our productivity and our sense of fulfillment from our work. With friends, a person with whom you must have spent many beautiful moments, tagging that person with one adjective based on an isolated experience could prove very costly. In the family scenario, tagging a person as unlikable or obnoxious may make it hard to feel happy and peaceful in your own house. Again, it's not meant to say that people can't be obnoxious. For example, if you are trapped in a relation under a roof with an abusive person, you may actually get to realise that much after you decide to get into a relation with him/her (if at all you get that opportunity to choose in the first place).
Assuming that not to be the case, one thing which does help a lot in such situations is to look at persons as a collection of, often unrelated, characteristics. A person may be lazy, but creative; lacking focus, but witty; insecure, but diligent; haphazard and disorganised, but sharp; rude, but honest ... you get it, right?
Controlling the Visceral Reaction
If we see that the relation with a person is going downhill, more often than not, it's because of a negative spiral of show of mutual dislike. When we see a sense of dislike in another person, we often feel hurt, and before anything, want to hurt back. This is a natural visceral reaction. But with practice, this can be controlled. If we realise that the dislike for us in that person may be because of a particular aspect of us, it (often) immediately attenuates the sudden urge to dislike back.
A person disliking us (or mostly certain aspect of us) isn't a clear evidence of that being a negative characteristic in us. Rather, it's most likely something that is causing the other person to feel threatened for some justified or unjustified reason. Here's an example of an unjustified reason: your being talented may be a disadvantage to the other person if both of you are in the same competitive space. Often, something good in us forces the other person to the unpleasant predicament to having to look at some of his/her negative aspect. For example, if you are quick at finishing tasks, while the other person takes longer, your showing quick results may force the other person to accept his/her weakness w.r.t. you. He/she would rather not do that, even if projecting it as a vain, show-off or beligerant attitude of yours. Another example: if you are good orator while the other person struggles to hold the interest of the audience even with great effort, that person may judge you as using flowery and fluffy language -- probably because he/she doesn't want to accept to himself/herself that he/she is not as good as you in communication skills.
In short, when a person shows dislike for us, instead of falling for the visceral reaction of disliking back even more intensely, it helps to critically look at the above aspects. If not anything else, it helps tone down and/or slow down our own reaction. This may be crucial in arresting a relation with another person in going into an irreversible negative spiral.
Reflecting
Note that, we are also subject to these reactions. So, I am not being
judgemental about anybody, nor am I assuming that we are free of these
vices. It helps knowing and accepting this. It's important not to loathe oneself for not being perfect. Self-loathing is often the biggest reason why we react in a toxic manner to others.
Expressing Appreciation
Treating people as a collection of disparate characteristics also allows us to look at their positive aspects in isolation. Assuming that the interpersonal dynamics haven't already degenerated to irreversible damage, there are opportunities coming our way every now and then to express this positive observation. Being able to look at different characteristics of the same person in isolation has a lot of benefits. For one, the other person realises that we haven't mentally given up on the relation from our side, and are willing to do our bit to save it. This itself is a great plus. Further, when the other person sees that we don't look at him/her entirely in a negative light, it's a proof that our dislike for them isn't so great as to have blinded you from looking at his/her positive aspects. Internally, when we genuinely see a positive aspect of the other person, it appears morally OK to appreciate that. Note that we don't praise or criticise a person but specific characteristics. Two negative and positive characteristics can co-exist in the same person. And it's completely OK to praise or criticise them at two points in time.
