A charge of bias arises when a Judge shows an act of partiality, see Akinfe v. The State (1988) 3 NWLR (pt.85) 729. Etymologically, bias means slant, personal inclination or preference; a one-sided inclination. It also means a pre-conceived opinion, a pre-disposition to decide a cause or an issue in a certain way, which does not leave the mind perfectly open to conviction. Bias creates a condition of mind which sways judgment and renders a Judge unable to exercise his functions impartially in a particular case. There is another expression and it is likelihood of bias. When a party in an action contends that there is likelihood of bias, he is anticipating that the Judge will be biased in the judicial process. The act of bias is not formalised. The act of bias is not concretised, but by the generality of the conduct of the Judge, the possibility of bias is overt. And the possibility is substantial. See generally LPDC v. Chief Fawehinmi (1985) 2 NWLR (Pt.7) 300. In a charge of bias, the integrity, honesty or fidelity of purpose and the Judge’s traditional role of holding the balance in the matter are questioned. He is branded or seen as one who leaves his exalted, respected and traditional arena of impartiality to descend unfairly on one of the parties outside all known canons of judicial discretion. The Judge is said to have a particular interest, a proprietory interest which cannot be justified on the scale of justice, as he parades that interest recklessly and parochially in the adjudication process to the detriment of the party he hates and to the obvious advantage of the party he likes. The Judge, at that level, is incapable of rational thinking and therefore rational judgment. His thoughts are blurred against the party he hates. He is poised for a fight, an uninstigated fight in which he is the main participant. The conduct of the Judge invariably and unequivocally points to one trend and it is that he will give judgment to the party he favours at all cost, come day or night, come rain or sunshine. Such is the terrible state of mind of the biased Judge or one who is likely to be biased.
— Niki Tobi, JCA. Nnamdi Eriobuna & Ors. V. Ikechukwu Obiorah (CA/E/77/99, 24 May 1999)