Opinion
MOSK, J.
Pursuant to Labor Code section 1160.8, petitioners seek a writ of review to set aside a decision and order of the Agricultural Labor Relations Board (Board). Because we granted petitioners’ petition to explicate the grounds upon which a finding of bias sufficient to compel disqualification may be based, we will recite only those facts relevant to the contention that the administrative law officer (ALO) erred when he failed to disqualify himself.
The Board’s general counsel initiated the underlying proceeding by filing complaints pursuant to Labor Code section 1160.2 alleging that petitioners—agricultural employers of workers covered by the Agricultural Labor Relations Act (ALRA)—had committed various unfair labor practices in connection with a union representation election held among petitioners’ employees. The general counsel charged petitioners with unlawfully discharging and demoting nine of their employees, with engaging in unlawful surveillance and interrogation of employees, and with otherwise restraining and interfering with the employees’ rights under the ALRA. The general counsel’s complaint and objections to the election filed by the United Farm Workers of America, AFL-CIO (UFW), which lost the election to the Teamsters Union, were consolidated for evidentiary hearing before an ALO.
The Board appointed Armando Menocal as a temporary ALO, pursuant to Labor Code section 1145, to conduct the hearings which took [786]*786place in December 1975 and January 1976. At that time, Menocal was an attorney in private practice with Public Advocates, Inc., a public interest law firm in San Francisco. Petitioners’ counsel first learned of this fact approximately one hour before the hearing commenced. He immediately moved to disqualify Menocal under California Administrative Code, title 8, section 20230.4, the then current regulation on disqualification of ALOs. After denying counsel’s request to question him about his employment, the ALO permitted counsel to make an oral affidavit as follows:
“Mr. Brown: My affidavit would be this that I understand Mr. Menocal is employed by Public Advocates which is a firm that I understand does a good deal of work in the area of employment discrimination. I believe they also do work on behalf of labor unions. It is my understanding that they do not work on behalf of employers. I understand the Hearing Officer is presently involved in an employment discrimination case in part involving race, involving Blacks, Orientals, and Mexican-Americans against the J. C. Penney Company, that Mr. Menocal has been involved in that case in the spring of 1974, and on those grounds and other grounds which I am sure I could possibly find out with further inquiry into the specific cases which Public Advocates is now handling, that there is certainly the appearance of bias, and I do not feel that my client can get the type of unbiased hearing that he is entitled to.”
After hearing argument on the motion, the ALO ruled as follows: “Mr. Brown, I deny your motion. I don’t believe it’s sufficient on its face. I have never represented the United Farm Workers Union, the Teamsters Union or any other union. I don’t believe I’ve ever represented a grower or farmer although, thinking back to the years I was in private practice, there is a chance that I once represented a grower against a packing house dealing with peaches that weren’t ripe.... A race discrimination case involving employment is not the same thing as a labor union dispute such as we have here and is not solely a suit against management. Indeed, in that case, we represent a class of both non-management and management personnel.”
During a week’s recess, petitioners appealed the disqualification decision to the Board and received an adverse ruling. They then petitioned the Court of Appeal, Fourth Appellate District, for a writ of certiorari which was summarily denied. When the hearings resumed, petitioners [787]*787renewed their motion to disqualify the ALO with the filing of the following written declaration of counsel:
“1. I am an attorney licensed to practice law in the State of California and represent Sam Andrews’ Sons in the above matters.
“2. I believe Armando Menocal, the hearing officer in the within matters, has a personal and professional bias and therefore, is not qualified within the meaning of Regulation Section 20230.4 to act as the hearing officer for the following reasons:
“(a) Mr. Menocal informed me on December 8, 1975, that he is presently employed with Public Advocates, a San Francisco law firm.
“(b) The 1974 and 1975 Docket sheets for Public Advocates, true and correct copies of which are attached hereto and incorporated herein as Exhibits A, B, and C establish that Public Advocates regularly represents Spanish-surnamed persons and farm workers against agricultural employers, other private employers, as well as governmental agencies in law suits and other legal matters challenging a variety of employment practices including national farm labor policies. Attention is called to 250 Farm Workers vs. Secretary of Labor and the comments attached thereto as set forth at page 12 of Exhibit ‘C.’
“(c) On December 8, 1975, Mr. Menocal informed me that since 1974 he has been involved in representing Spanish-surnamed persons in a suit challenging the employment practices of J. C. Penney Company. Reference is hereby specifically made to the comments on Sebastian v. J. C. Penney Company, Inc. as set forth at item 12 of Exhibit ‘A’ attached hereto.
“I declare under penalty of perjury that the foregoing is true and correct.
“Executed at Los Angeles, California, on December 11, 1975.”
Upon examining this material, the ALO concluded: “I do not find that the declaration or the exhibits attached to it are sufficient to show any grounds for bias or disqualification. The motion is denied.”
The hearings proceeded to the merits of the unfair labor practice charges, and the ALO filed a recommended decision adverse to peti[788]*788tioners on most of the major issues. The Board issued its final decision without treating the disqualification issue; it essentially adopted the ALO’s findings and recommendations. The Board did declare that it had considered and made an independent review of the entire record in the case.
Although petitioners make a number of supplementary arguments, we will address only their major contention that the ALO improperly failed to disqualify himself pursuant to the Board’s regulation 20230.4. As will appear, we conclude that contention lacks both legal and factual support.
I.
At the time of the hearings, regulation 20230.4 governed the disqualification of ALOs. It provided:
“Disqualification of Administrative Law Officer When Conducting a Hearing. An administrative law officer may withdraw from a proceeding whenever he deems himself disqualified. Any party may request the administrative law officer at any time following his designation, and before filing of his decision, to withdraw on ground of personal bias or disqualification by filing with him promptly upon the discovery of the alleged fact, a timely affidavit setting forth in detail the matters alleged to constitute grounds for disqualification. If, in the opinion of the administrative law officer such affidavit is filed with due diligence and is sufficient on its face, he shall forthwith disqualify himself and withdraw from the proceeding. If the administrative law officer does not disqualify himself and withdraw from the proceeding, he shall so rule upon the record, stating the grounds for his ruling and proceed with the hearing, or, if the hearing has closed, he shall proceed with issuance of his decision, and the provisions of section 20220.2 with respect to review of rulings of administrative law officers, shall thereupon apply.”1
Petitioners first contend that regulation 20230.4 was the analogue of Code of Civil Procedure section 170.6 and should be interpreted accord[789]*789ingly to give them the right to automatically disqualify an ALO. The texts of the two sections lend no support to such construction. Code of Civil Procedure section 170.6 provides in substance that any party or attorney to a civil or criminal action has one opportunity to make a motion to disqualify the assigned judge, supported by an affidavit that the judge is prejudiced against such party or attorney or the interest thereof so that the affiant cannot or believes he cannot obtain an impartial trial; if the motion is timely and in proper form, the judge must recuse himself without further proof and the case must be reassigned to another judge. As we stated in McCartney v. Commission on Judicial Qualifications (1974) 12 Cal.3d 512, 531 [116 Cal.Rptr. 260, 526 P.2d 268], and reemphasized in Solberg v. Superior Court (1977) 19 Cal.3d 182, 193 [137 Cal.Rptr. 460, 561 P.2d 1148], “‘It is well recognized that in enacting Code of Civil Procedure section 170.6 the Legislature guaranteed to litigants an extraordinary right to disqualify a judge. The right is “automatic” in the sense that a good faith belief in prejudice is alone sufficient, proof of facts showing actual prejudice not being required.’” (Italics in original.)
Regulation 20230.4 provided no such extraordinary right. It required the ALO to disqualify himself only when, in the opinion of the ALO, the affidavit setting forth the grounds of personal bias or disqualification was sufficient on its face. Thus, under regulation 20230.4, although the ALO was not permitted to contest the allegations of bias, he was not compelled to disqualify himself unless in his opinion the moving party had made a prima facie showing of bias. Clearly then, the regulation did not afford a party the virtually automatic disqualification provided by Code of Civil Procedure section 170.6. We must therefore ascertain whether the facts alleged here constitute a showing of bias.2
II
Petitioners imply that a ground for bias was the ALO’s practice of law with a firm which in the past had represented individual farm workers in a suit against the Secretary of Labor and which engaged in employment discrimination suits on behalf of Mexican-Americans. [790]*790From this, it appears we are to infer that the ALO has some philosophical or political inclination that would make it impossible for him to conduct hearings impartially. Even if the nature of a lawyer’s practice could be taken as evidence of his political or social outlook,3 such evidence, as will appear, is irrelevant to prove bias. Therefore, rather than review the nature of the cases in which the ALO or his firm has participated or attempt to identify what viewpoints those cases might possibly suggest, we will simply reaffirm the general principles that make doing so unnecessary.
The right to an impartial trier of fact is not synonymous with the claimed right to a trier completely indifferent to the general subject matter of the claim before him. As stated in Evans v. Superior Court (1930) supra, 107 Cal.App. 372, 380, the word bias refers “‘to the mental attitude or disposition of the judge towards a party to the litigation, and not to any views that he may entertain regarding the subject matter involved.’” In an administrative context, Professor Davis has written that “Bias in the sense of crystallized point of view about issues of law or policy is almost universally deemed no ground for disqualification.” (2 Davis, Administrative Law Treatise (1st ed. 1958) p. 131; also see United States v. Morgan (1941) 313 U.S. 409, 420-421 [85 L.Ed. 1429, 1434-1435, 61 S.Ct. 999]; Trade Comm’n. v. Cement Institute (1948) 333 U.S. 683, 700-703 [92 L.Ed. 1010, 1034-1036, 68 S.Ct. 793].) This long established, practical rule is merely a recognition of the fact that anyone acting in a judicial role will have attitudes and preconceptions toward some of the legal and social issues that may come before him.
Petitioners revive the same discarded stereotype of bias relative to disqualifying a judicial officer that Judge Jerome Frank addressed many years ago: “Democracy must, indeed, fail unless our courts try cases fairly, and there can be no fair trial before a judge lacking in impartiality and disinterestedness. If, however, ‘bias’ and ‘partiality’ be defined to mean the total absence of preconceptions in the mind of the judge, then no one has ever had a fair trial and no one ever will. The human mind, even at infancy, is no blank piece of paper. We are born with predispositions; and the process of education, formal and informal, [791]*791creates attitudes in all men which affect them in judging situations, attitudes which precede reasoning in particular instances and which, therefore, by definition, are prejudices.... Interests, points of view, preferences, are the essence of living. Only death yields complete dis-passionateness, for such dispassionateness signifies utter ‘indifference.” (In re J. P. Linahan (2d Cir. 1943) 138 F.2d 650, 651-652.)
Not only would it be extraordinary to find a judicial officer who is totally without a thought on all issues, the discovery of such a rare intellectual eunuch would suggest an adverse reflection on his qualifications. For example, in a case in which he refused to recuse himself even though as an assistant attorney general he had previously expressed his legal opinion on the issues involved, Justice Rehnquist stated, “Proof that a Justice’s mind at the time he joined the Court was a complete tabula rasa in the area of constitutional adjudication would be evidence of lack of qualification, not lack of bias.” (Laird v. Tatum (1972) 409 U.S. 824, 835 [34 L.Ed.2d 50, 59, 93 S.Ct. 7] (memorandum of Rehnquist, J.).) Similarly, it would be untenable for this court to insist upon selection only of ALOs who have never thought about or expressed an opinion on the broad social, economic or legal issues that inherently underlie a labor dispute.
Therefore, even if the viewpoint attributed to an ALO could be inferred from the nature of his legal practice or his clients—which we do not concede—that would be no ground for disqualification. A trier of fact with expressed political or legal views cannot be disqualified on that basis alone even in controversial cases. The more politically or socially sensitive a matter, the more likely it is that the ALO, like most intelligent citizens, will have at some time reached an opinion on the issue. This is an unavoidable feature of a legal system dependent on human beings rather than robots for dispute resolution.
III.
Even assuming, arguendo, the political or legal views of an ALO could result in an appearance of bias, we cannot hold, as requested by petitioners, that a mere appearance of bias is a ground for the disqualification of a judicial officer.4 Code of Civil Procedure section 170, [792]*792subdivision 5, requires disqualification “when it is made to appear probable that, by reason of bias or prejudice of such justice or judge a fair and impartial trial cannot be had before him.” Despite some imprecise language in several Court of Appeal opinions, no court in California has ever interpreted section 170, subdivision 5, to mean that an appearance of bias, in the sense of a subjective belief in its existence, is a sufficient ground for disqualification. Appearance, after all, is generally in the eye of the beholder.
The proper analysis of the section was set forth in Ensher, Alexander & Barsoom v. Ensher (1964) 225 Cal.App.2d 318, 322 [37 Cal.Rptr. 327]: “In order for the judge to be disqualified, the prejudice must be against a particular party [citations] and sufficient to impair the judge’s impartiality so that it appears probable that a fair trial cannot be held.” (Italics added.) The case thus suggests a two-tier inquiry in determining whether the bias alleged by a party is a sufficient ground for disqualification.
The first inquiry consists of deciding whether the moving party has set forth legally sufficient facts to demonstrate the bias of the judicial officer. After that determination, the challenged judicial officer or a reviewing court must still decide whether such bias will render it probable that a fair trial cannot be held before that judge. In other words, the bias or prejudice must be “sufficient to impair the judge’s impartiality.” To be sure, once the existence of bias has been established, it will not be difficult to demonstrate that a fair and impartial trial or hearing appears improbable. Nonetheless, this analysis is helpful in explaining that the threshold determination cannot be satisfied and has never been satisfied by an allegation of the mere appearance of bias.
A party must allege concrete facts that demonstrate the challenged judicial officer is contaminated with bias or prejudice. “Bias and prejudice are never implied and must be established by clear averments.” (Shakin v. Board of Medical Examiners (1967) 254 Cal.App.2d 102, 117 [62 Cal.Rptr. 274, 23 A.L.R.3d 1398].) Indeed, a party’s unilateral perception of an appearance of bias cannot be a ground for disqualification unless we are ready to tolerate a system in which disgruntled or dilatory litigants can wreak havoc with the orderly administration of dispute-resolving tribunals. “A judge should not be disqualified lightly or on frivolous allegations or mere conclusions.” (Mackie v. Dyer (1957) 154 Cal.App.2d 395, 400 [316 P.2d 366].)
[793]*793Even the cases that loosely speak of an appearance of bias in judicial conduct hold no less. In Pratt v. Pratt (1903) 141 Cal. 247, 252 [184 P. 956], this court reversed an order of the trial court because of the judge’s failure to disqualify himself, stating, “The trial of a case should not only be fair in fact, but it should also appear to be fair.” The appearance of unfairness properly resented in Pratt was the trial judge’s comment, regarding the use of a daughter to impeach the testimony of her mother, that “T don’t know anything that would condemn your client in my eyes so completely as to put that girl on the stand ....’” (Id. at p. 250.) Such prejudgment of testimony is more than a mere appearance of bias; it evidences actual bias.
In Pacific etc. Conference of United Methodist Church v. Superior Court (1978) 82 Cal.App.3d 72, 87 [147 Cal.Rptr. 44], the court spoke of a reasonable appearance of prejudgment. Here again, however, there was more involved than appearance of prejudgment: the challenged judge had actually written a letter to the parties during the pretrial phase of the case stating, “T believe the plaintiffs’ claims ... are meritorious and that they will in all probability prevail at the time of trial.’” (Id. at pp. 76-77.)
Thus, our courts have never required the disqualification of a judge unless the moving party has been able to demonstrate concretely the actual existence of bias.5 We cannot now exchange this established principle for one as vague, unmanageable. and laden with potential mischief as an “appearance of bias” standard, despite our deep concern for the objective and impartial discharge of all judicial duties in this state.
[794]*794The foregoing considerations, of course, are equally applicable to the disqualification of a judicial officer in the administrative system. Indeed, the appearance of bias standard may be particularly untenable in certain administrative settings. For example, in an unfair labor practice proceeding the Board is the ultimate factfinder, not the ALO. (Lab. Code, § 1160.3; Royal Packing Co. v. Agricultural Labor Relations Bd. (1980) 101 Cal.App.3d 826, 836 [161 Cal.Rptr. 870].) We therefore fail to see how a mere subjective belief in the ALO’s appearance of bias, as distinguished from actual bias, can prejudice either party when the Board is responsible for making factual determinations, upon an independent review of the record. In the case at bar the Board declared it did undertake such an independent review of the entire record. (See, e.g., Serenko v. Bright (1968) 263 Cal.App.2d 682, 691 [70 Cal.Rptr. 1].)
IV.
Appellants further contend that the temporary status of the ALO herein should be recognized as a factor in the disqualification analysis because of his increased susceptibility to bias due to the potential influences of a continuing legal practice. However, we know of no case, nor have we been cited to any, that stands for the proposition that a pro tempore judicial officer is peculiarly vulnerable to a disqualification challenge because he is engaged in the practice of law before and after his temporary public service.
Labor Code section 1145 provides: “The board may appoint ... such attorneys, hearing officers, administrative law officers, and other employees as it may from time to time find necessary for the proper performance of its duties. Attorneys appointed pursuant to this section may, at the discretion of the board, appear for and represent the board in any case in court. All employees appointed by the board shall perform their duties in an objective and impartial manner without prejudice toward any party subject to the jurisdiction of the board.” It, is not disputed that this statute gives the Board the power to use temporary ALOs. Clearly then, the Legislature has deemed it proper for temporary employees to act in a judicial capacity as long as they conduct themselves “in an objective and impartial manner.” The Legislature has thus asked no more of temporary ALOs than it or the courts have ever demanded from permanent judicial officers. We have no authority to apply a more rigorous standard than that prescribed in i [795]*795legislative enactment by allowing an ALO’s temporary status to to be used as an element in a showing of bias sufficient for disqualification.6
V.
Petitioners finally contend that bias appears on the face of the ALO’s findings and recommended decision. However, because this contention rests on an erroneous legal foundation, there is no need for us to examine the substance of his report.
It is first asserted that bias may be shown by the fact that some of a hearing officer’s findings are not supported by substantial evidence. The fallacy of this assertion is explained in Gellhorn et al., Administrative Law—Cases and Comments (7th ed. 1979) page 767: “If the fact finder has allegedly credited unsubstantial evidence while disregarding utterly irrefutable evidence, the issue before a reviewing court should not be whether the fact finder was biased, but whether his findings of fact are supported by substantial evidence on the whole record.” (See also, A. O. Smith Corporation v. N. L. R. B. (7th Cir. 1965) 343 F.2d 103, 110.) If the challenged findings are not supported by substantial evidence, it is the duty of the reviewing court to overturn those findings and it will do so because of failure of proof, not because the results per se establish bias.
There is no reason to explore the heart and mind of the ALO when effective relief is readily available if the reviewing court concludes a finding is unsupported by substantial evidence. To hold otherwise would encourage a losing party to raise the specter of bias indiscriminately, whenever he could demonstrate that one finding of fact in a large administrative record was not sufficiently supported. We decline to cast that cloud of uncertainty over adjudicative proceedings.
But, petitioners assert, that bias may be established where the record shows the hearing officer uniformly believed evidence introduced by the union and uniformly disbelieved evidence produced by the employer. This contention is contrary to the great weight of authority. For example, in McEwen v. Occidental Life Ins. Co. (1916) 172 Cal. 6, 11 [155 P. 86], it was held that numerous and continuous rulings against a [796]*796litigant, even when erroneous, form no ground for a charge of bias or prejudice. This rule is tenable in both a judicial and an administrative context. To fulfill his duty, an ALO must make choices when conflicting evidence is offered; thus, his reliance on certain witnesses and rejection of others cannot be evidence of bias no matter how consistently the ALO rejects or doubts the testimony produced by one of the adversaries. As the Supreme Court declared, “total rejection of an opposed view cannot of itself impugn the integrity or competence of a trier of fact.” (Labor Board v. Pittsburg S. S. Co. (1949) 337 U.S. 656, 659 [93 L.Ed.2d 1602, 1606, 69 S.Ct. 1283]; see also International U., United Auto., A. & A. I. Wkrs. v. N. L. R. B. (D.C.Cir. 1971) 455 F.2d 1357, 1368.)7
It follows that the ALO did not err in refusing to disqualify himself. The Court of Appeal, however, confined its decision to this issue; it did not review the substance of the petition. Accordingly, the proceeding is retransferred to that court for a determination of the remaining issues presented by the petition for writ. (See Taylor v. Union Pac. R. R. Corp. (1976) 16 Cal.3d 893, 901 [130 Cal.Rptr. 23, 549 P.2d 855].)
Tobriner, Acting C. J., and Files, J.,
Assigned by the Acting Chairperson of the Judicial Council.