We have the choice to activate "Reputation". I've called mine Kudos.
Go to Modules
Scroll down to Points and Reputation
Once you have set the reputation up then in the mini profiles it shows how many you have.
To give a plus or minus reputation/karma each post has the links on the top right of each post.
I have deleted the minus reputation so you will only see the "plus" one, which I changed from the + sign to a coloured Heart.
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