I searched the RG questions that refer to down-vote, but I found only questions concerning perception of this option. I'm interested to understand why you could down-vote (or not down-vote) a question or an answer.
I exactly don't know who is doing this illiteracy, by downvoting the answers and the questions. Perhaps this is their habit from birth. They should to be blocked permanently from RESEARCHGATE. They actually don't know anything of science, they are really just at here to spoil the environment of this RG website. And one more strict order to the down-voters from me that, if you want to down vote any contribution of anybody, you have to give the reason for which you see that thing is insignificant. Otherwise be sure that, anonymous down voting makes you silly & insignificant to other people.
Thank you for the answer. I did not see a question who have downvote, but I'm agree that a downvote must have a justification. Maybe this option (downvoting) should be disabled, because any response is a reaction and any reaction can be analyzed.
This happens with me rarely. However, it depends on one's understanding of the topic, the question that is to answer in the right manner and the answer provided. An answer, that makes no contribution to the solution of the problem being highlighted in the question, should be down-voted. Otherwise, false information will spread among the fellows who are following the question in the hope to get the required answer.
Thanks to all RG members who answered. It been some time that RG disabled the option for downvote and enabled the option "Recommend". So my question is no longer actual.