No legal catchphrase is more often repeated than that determinations by a trial judge (or jury) whether to believe or disbelieve a witness can be overturned on appeal only in extraordinary circumstances. The reason is said to be the inestimable value, in assessing credibility, of seeing and hearing the witness rather than reading a transcript of his testimony, since the transcript eliminates clues to veracity that are supplied by tone of voice, hesitation, body language, and other nonverbal expressions.

The trial judge has sat through the entire case and his ultimate judgment reflects this total familiarity with the evidence. The insight gained by the trial judge who has lived with the case for several days, weeks or even months may be far deeper than that of the Court of Appeal whose view of the case is much more limited and narrow, often being shaped and distorted by the various orders or rulings being challenged.

The need for appellate caution in reversing the [trial] judge’s evaluation of the facts is based upon much more solid grounds than professional courtesy. It is because specific findings of fact, even by the most meticulous judge, are inherently an incomplete statement of the impression which was made upon him by the primary evidence. His expressed findings are always surrounded by a penumbra of imprecision as to emphasis, relative weight, minor qualification and nuance … of which time and language do not permit exact expression, but which may play an important part in the judge’s overall evaluation.

This is traditionally and rightly explained by reference to good sense, namely that the trial judge has the benefit of assessing the witnesses and actually hearing and considering their evidence as it emerges. Consequently, where a trial judge has reached a conclusion on the primary facts, it is only in a rare case, such as where that conclusion was one (i) which there was no evidence to support, (ii) which was based on a misunderstanding of the evidence, or (iii) which no reasonable judge could have reached, that an appellate tribunal will interfere with it. This can also be justified on grounds of policy (parties should put forward their best case on the facts at trial and not regard the potential to appeal as a second chance), cost (appeals on fact can be expensive), delay (appeals on fact often take a long time to get on), and practicality (in many cases, it is very hard to ascertain the facts with confidence, so a second, different, opinion is no more likely to be right than the first).

This is one of those commonsense propositions that may well be false. Nonverbal clues to veracity are unreliable and distract a trier of fact (or other observer) from the cognitive content of the witness’s testimony. Yet it would occur to few judges to question the proposition that the trial judge has superior ability to judge credibility than the appellate judge, because nothing in the culture of the law encourages its insiders to be sceptical of oft-repeated propositions accepted as the old-age wisdom of the profession, and because appellate judges (indeed all judges) usually are happy to hand off responsibility for deciding to another adjudicator. [Citations omitted.]

No longer, however, are they technologically constrained to do so. Witnesses’ testimony could be video-taped and the videotapes of their testimony made available to an appellate judge who thought demeanor important in assessing the truthfulness of testimony.

A judge who observes the demeanour of the witnesses while they are being examined by counsel has from his detached position a much more favourable opportunity of forming a just appreciation than a judge who himself conducts the examination. If he takes the latter course he, so to speak, descends into the arena and is liable to have his vision clouded by the dust of the conflict. Unconsciously he deprives himself of the advantage of calm and dispassionate observation. It is further to be remarked, as everyone who has had experience of these matters knows, that the demeanour of a witness is apt to be very different when he is being questioned by the judge from what it is when he is being questioned by counsel, particularly when the judge’s examination is, as it was in the present case, prolonged and covers practically the whole of the crucial matters which are in issue.

An obvious difficulty which affects allegations and oral evidence based on recollection of events which occurred several years ago is the unreliability of human memory.

While everyone knows that memory is fallible, I do not believe that the legal system has sufficiently absorbed the lessons of a century of psychological research into the nature of memory and the unreliability of eyewitness testimony. One of the most important lessons of such research is that in everyday life we are not aware of the extent to which our own and other people’s memories are unreliable and believe our memories to be more faithful than they are. Two common (and related) errors are to suppose: (1) that the stronger and more vivid is our feeling or experience of recollection, the more likely the recollection is to be accurate; and (2) that the more confident another person is in their recollection, the more likely their recollection is to be accurate.

Underlying both these errors is a faulty model of memory as a mental record which is fixed at the time of experience of an event and then fades (more or less slowly) over time. In fact, psychological research has demonstrated that memories are fluid and malleable, being constantly rewritten whenever they are retrieved. This is true even of so-called “flashbulb” memories, that is memories of experiencing or learning of a particularly shocking or traumatic event. (The very description “flashbulb” memory is in fact misleading, reflecting as it does the misconception that memory operates like a camera or other device that makes a fixed record of an experience.) External information can intrude into a witness’s memory, as can his or her own thoughts and beliefs, and both can cause dramatic changes in recollection. Events can come to be recalled as memories which did not happen at all or which happened to someone else (referred to in the literature as a failure of source memory).

Memory is especially unreliable when it comes to recalling past beliefs. Our memories of past beliefs are revised to make them more consistent with our present beliefs. Studies have also shown that memory is particularly vulnerable to interference and alteration when a person is presented with new information or suggestions about an event in circumstances where his or her memory of it is already weak due to the passage of time.

The process of civil litigation itself subjects the memories of witnesses to powerful biases. The nature of litigation is such that witnesses often have a stake in a particular version of events. This is obvious where the witness is a party or has a tie of loyalty (such as an employment relationship) to a party to the proceedings. Other, more subtle influences include allegiances created by the process of preparing a witness statement and of coming to court to give evidence for one side in the dispute. A desire to assist, or at least not to prejudice, the party who has called the witness or that party’s lawyers, as well as a natural desire to give a good impression in a public forum, can be significant motivating forces.

Considerable interference with memory is also introduced in civil litigation by the procedure of preparing for trial. A witness is asked to make a statement, often (as in the present case) when a long time has already elapsed since the relevant events. The statement is usually drafted for the witness by a lawyer who is inevitably conscious of the significance for the issues in the case of what the witness does nor does not say. The statement is made after the witness’s memory has been “refreshed” by reading documents. The documents considered often include statements of case and other argumentative material as well as documents which the witness did not see at the time or which came into existence after the events which he or she is being asked to recall. The statement may go through several iterations before it is finalised. Then, usually months later, the witness will be asked to re-read his or her statement and review documents again before giving evidence in court. The effect of this process is to establish in the mind of the witness the matters recorded in his or her own statement and other written material, whether they be true or false, and to cause the witness’s memory of events to be based increasingly on this material and later interpretations of it rather than on the original experience of the events.

It is not uncommon (and the present case was no exception) for witnesses to be asked in cross-examination if they understand the difference between recollection and reconstruction or whether their evidence is a genuine recollection or a reconstruction of events. Such questions are misguided in at least two ways. First, they erroneously presuppose that there is a clear distinction between recollection and reconstruction, when all remembering of distant events involves reconstructive processes. Second, such questions disregard the fact that such processes are largely unconscious and that the strength, vividness and apparent authenticity of memories is not a reliable measure of their truth.

If I try to tell you what happened to me in ’91, I’ll have to guess about certain things, I’ll have to make up certain things, because I can’t remember everything. And certain memories are not datable. You and I might remember our lunch, but some years from now we won’t remember it was on a Friday. I will not connect it with what happened this morning because they are discontinuous events. To tell a story, you have to — not falsify — but you have to assemble and disassemble. Memories are creative. To treat memory as a fact is nonsense. It’s inescapably fiction.

[T]he ability to tell a coherent, plausible and assured story, embellished with snippets of circumstantial detail and laced with occasional shots of life-like forgetfulness, is very likely to impress any tribunal of fact. But it is also the hallmark of the confidence trickster down the ages.

To be capable of amounting to corroboration the lie told out of court must first of all be deliberate. Secondly it must relate to a material issue. Thirdly the motive for the lie must be a realisation of guilt and a fear of the truth. The jury should in appropriate cases be reminded that people sometimes lie, for example, in an attempt to bolster up a just cause, or out of shame or out of a wish to conceal disgraceful behaviour from their family.

“Credibility” involves wider problems than mere “demeanour” which is mostly concerned with whether the witness appears to be telling the truth as he now believes it to be. Credibility covers the following problems. First, is the witness a truthful or untruthful person? Secondly, is he, though a truthful person, telling something less than the truth on this issue, or, though an untruthful person, telling the truth on this issue? Thirdly, though he is a truthful person telling the truth as he sees it, did he register the intentions of the conversation correctly and, if so, has his memory correctly retained them? Also, has his recollection been subsequently altered by unconscious bias or wishful thinking or by over-much discussion of it with others? Witnesses, especially those who are emotional, who think that they are morally in the right, tend very easily and unconsciously to conjure up a legal right that did not exist. It is a truism, often used in accident cases, that with every day that passes the memory becomes fainter and the imagination becomes more active. For that reason a witness, however honest, rarely persuades a Judge that his present recollection is preferable to that which was taken down in writing immediately after the accident occurred. Therefore, contemporary documents are always of the utmost importance. And lastly, although the honest witness believes he heard or saw this or that, is it so improbable that it is on balance more likely that he was mistaken? On this point it is essential that the balance of probability is put correctly into the scales in weighing the credibility of a witness. And motive is one aspect of probability. All these problems compendiously are entailed when a Judge assesses the credibility of a witness; they are all part of one judicial process. And in the process contemporary documents and admitted or incontrovertible facts and probabilities must play their proper part.

In the light of these considerations, the best approach for a judge to adopt in the trial of a commercial case is, in my view, to place little if any reliance at all on witnesses’ recollections of what was said in meetings and conversations, and to base factual findings on inferences drawn from the documentary evidence and known or probable facts. This does not mean that oral testimony serves no useful purpose — though its utility is often disproportionate to its length. But its value lies largely, as I see it, in the opportunity which cross-examination affords to subject the documentary record to critical scrutiny and to gauge the personality, motivations and working practices of a witness, rather than in testimony of what the witness recalls of particular conversations and events. Above all, it is important to avoid the fallacy of supposing that, because a witness has confidence in his or her recollection and is honest, evidence based on that recollection provides any reliable guide to the truth.

[T]he importance of the part played by those advantages in assisting the judge to any particular conclusion of fact varies through a wide spectrum from, at one end, a straight conflict of primary fact between witnesses, where credibility is crucial and the appellate court can hardly ever interfere, to, at the other end, an inference from undisputed primary facts, where the appellate court is in just as good a position as the trial judge to make the decision.

Where the honesty of a witness is a central issue in the case, one is close to the former end of the spectrum as the advantage which the trial judge has had in assessing the credibility and reliability of oral evidence is not available to the appellate court. Where a trial judge is able to make his findings of fact based entirely or almost entirely on undisputed documents, one will be close to the latter end of the spectrum.

One reason why so much forensic acrimony was generated, with the consequential burgeoning of costs, was that the Deputy District Judge at the first appointment on 9 November 2012 permitted each party to have their own expert to value the husband’s business interests, notwithstanding the terms of Part 25 FPR [Family Procedure Rules 2010 (UK)] which clearly stated then (and even more strongly states now — see PD 25D para 2.1) that a SJE should be used “wherever possible”. Not “ideally” or “generally” but “wherever possible”. In this case the forensic accountants have filed a total of no fewer than six expert reports and have prepared a joint statement setting out their extensive disagreements. They have charged a total of £154,000 in fees. The husband has been permitted during the course of the case to ditch his expert and to instruct a new one.

It can be seen how the failure to appoint a SJE resulted in extremely partial and partisan positions being adopted by the experts who seem to have forgotten that their first duty is to the court and that, notwithstanding the large fees they are paid, their role is not to act as a gladiator on behalf of their client.

A lawyer is not allowed to pay a lay witness to testify; the potential for corruption is obvious. But he may pay an expert witness — and the potential for corruption is obvious.

Lawyers resist a judge’s [sic] appointing an expert even if both sides are satisfied that the expert is neutral and competent and can communicate with a jury, as academics (and not only academics) usually can. For the lawyers aren’t interested whether the judge or jury understands their case; they’re interested in winning, and so they hire experts (and pay them very well) whom they think a judge or jury will find persuasive.

A further problem with expert witnesses is that for many of them litigation is their ordinary, even their only, work. Their technical skills may be minimal, their real skill being theatrical — the ability to charm or dazzle a jury. [Emphasis in original.]

Where the application is for a decree of nullity of a marriage of an opposite sex couple on the ground of incapacity to consummate or wilful refusal to do so, the court must determine whether medical examiners should be appointed to examine the parties or either of them.

All this shows that it was a made up affairs [sic] and the respondent does not suffer from impotency organic or psychological qua the petitioner … I am of the considered view that the petition has been filed by the petitioner in collusion with the respondent.

It may be stated here that the husband was examined by a board of doctors on two occasions. Their reports are on the record. In one of the reports the doctors found that the husband was unable to produce erection when asked to masturbate. On the second occasion they found that there was nothing which could prove that he was impotent. These reports were not tendered in evidence on behalf of either side and, therefore, they do not constitute proof in the case.

[T]here may be cases where a person may have invincible repugnance to the act with a particular individual, though generally capable of having sexual union with others. Where owing to psychological or mental reasons a person is impotent quoad hanc it is not necessary to show universal impotency. In these types of cases the impotency arising from that fact would be within the exclusive knowledge of these spouses and it would be difficult to test it by medical evidence.

I do not think that the learned Additional District Judge was right … drawing an adverse inference because of the non-examination of the doctors by the wife. In view of the admission of the husband himself I think no further evidence was called for. It is not possible for the doctors, I think, in all cases to find out whether a certain person has a sexual aversion to a particular woman or the wife. The doctors can find out whether there is malformation or structural defect in the genitals of a man.

It is plainly important that, conformably with the ideal of justice in the individual case, there be general consistency from one case to another of underlying notions of what is just and appropriate in particular circumstances. Otherwise, the law would, in truth, be but the “lawless science” of “a codeless myriad of precedent” and “a wilderness of single instances” of which Lord Tennyson wrote in his poem “Aylmer’s Field”.

The job of judges is to apply the law, not to indulge their personal preferences. There are areas in which they are required to exercise a discretion, but such discretions are much more closely constrained than is always acknowledged.

However, as Ormrod LJ observed, [Martin v Martin [1978] Fam 12] the courts’ pronouncements on a provision like section 7 “can never be better than guidelines”. This is because, as Gibbs CJ explained, [Mallett v Mallett(1984) 156 CLR 605 at 609] the courts “cannot put fetters on the discretionary power which the Parliament has left largely unfettered”. Dealing with the natural tension existing between the need for flexibility on the one hand and the desire for consistency on the other, Brennan J stated:

The only compromise between idiosyncracy [sic] in the exercise of the discretion and an impermissible limitation of the scope of the discretion is to be found in the development of guidelines from which a judge may depart when it is just and equitable to do so — guidelines which are not rules of universal application, but which are generally productive of just and equitable orders. [Norbis v Norbis (1986) 161 CLR 513 at 538]

As his Honour pointed out, Lord Denning MR addressed the problem of guiding the exercise of an unfettered judicial discretion in Ward v James [1966] 1 QB 273 at [295] in the following terms:

The cases all show that, when a statute gives discretion, the courts must not fetter it by rigid rules from which a judge is never at liberty to depart. Nevertheless the courts can lay down the considerations which should be borne in mind in exercising the discretion, and point out those considerations which should be ignored. This will normally determine the way in which the discretion is exercised, and thus ensure some measure of uniformity of decision. From time to time the considerations may change as public policy changes, and so the pattern of decision may change: this is all part of the evolutionary process.

If, and only if, the court considers that it is in the best interests of the child to make her (or him) a party, the door opens on a discretion to make her so. No doubt it is the sort of discretion, occasionally found in procedural rules, which is more theoretical than real: the nature of the threshold conclusion will almost always drive the exercise of the resultant discretion.

But the fact that the case involves factual evaluation and a value judgment does not of itself mean the decision is discretionary. In any event, as the Court of Appeal correctly said, the assessment of what was in the best interests of the children in the present case did not involve an appeal from a discretionary decision. The decision of the High Court was a matter of assessment and judgment not discretion, and so was that of the Family Court.

These and other concerns … are inherent in the exercise in which judges administering ss 4 and 5 of the [Care of Children] Act [2004] are involved. Lack of predictability, particularly in difficult or marginal cases, is inevitable and the so-called wide discretion given to judges is the corollary of the need for individualised attention to be given to each case. As we have seen, the court is not in fact exercising a discretion; it is making an assessment and decision based on an evaluation of the evidence. It is trite but perhaps necessary to say that judges are required to exercise judgment. The difficulties which are said to beset the field are not conceptual or legal difficulties; they are inherent in the nature of the assessments which the courts must make. The judge’s task is to determine and evaluate the facts, considering all relevant s 5 principles and other factors, and then to make a judgment as to what course of action will best reflect the welfare and best interests of the children. While that judgment may be difficult to make on the facts of individual cases, its making is not assisted by imposing a gloss on the statutory scheme.

G v G (Minors: Custody Appeal) [1985] 1 WLR 647 was a dispute between parents as to which of them should have residence of the children. Lord Fraser of Tullybelton gave the classic exposition of the role of the appellate court in reviewing a trial judge’s order in a dispute between members of a family about arrangements for a child. He described the order, at p 649, as having been made in the exercise of the judge’s discretion. This classification, which was not controversial, is hard-wired into the mind-set of family lawyers in England and Wales; and, although in Kacem v Bashir [2011] 2 NZLR 1, the Supreme Court of New Zealand made an interesting suggestion, at para 32, that the decision in such a case was evaluative as opposed to discretionary, this is not the moment to consider whether — subject to para 45 below — to depart from the conventional classification or the consequences, if any, of doing so.

What does “plainly” add to “wrong”? Either the word adds nothing or it serves to treat the determination under challenge with some slight extra level of generosity apt to one which is discretionary but not to one which is evaluative.