biased
adjective
(also biassed) uk/ˈbaɪəst/ uspreferring or disliking someone or something more than someone or something else, in a way that means that they are treated unfairly:
biased against sb/sth He believes the American justice system is biased against blacks.
biased in favour of sb/sth They claimed that the settlement was biased in favour of corporate clients.
giving results that are not accurate because information has not been collected correctly:
A biased sample of interviewees has a set of characteristics that are different from those of the population as a whole.
Compare
unbiased