Feynman has a bunch of ideas in common with Popper! Here are some examples from his speech "The Value of Science". Read the whole thing.

http://alexpetrov.com/memes/sci/value.html

When a scientist doesn't know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty darn sure of what the result is going to be, he is in some doubt. We have found it of paramount importance that in order to progress we must recognize the ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty -- some most unsure, some nearly sure, none absolutely certain.

The idea that no one really knew how to run a government led to the idea that we should arrange a system by which new ideas could be developed, tried out, tossed out, more new ideas brought in; a trial and error system ... doubt and discussion were essential to progress into the unknown. If we want to solve a problem that we have never solved before, we must leave the door to the unknown ajar.

we can make grave errors that can stunt our growth for a long time. This we will do if we say we have the answers now, so young and ignorant; if we suppress all discussion, all criticism ... and thus doom man for a long time to the chains of authority, confined to the limits of our present imagination. It has been done so many times before.

It is our responsibility as scientists ... to teach how doubt is not to be feared but welcomed and discussed

This next quote isn't Popperian, but I think it's great:

When we read about this in the newspaper, it says, "The scientist says that this discovery may have importance in the cure of cancer." The paper is only interested in the use of the idea, not the idea itself. Hardly anyone can understand the importance of the idea, it is so remarkable. Except that, possibly, some children catch on. And when a child catches on to an idea like that, we have a scientist. These ideas do filter down (in spite of all the conversation about TV replacing thinking), and lots of kids get the spirit -- and when they have the spirit you have a scientist. It's too late for them to get the spirit when they are in our universities, so we must attempt to explain these ideas to children.

These are Steve Job quotes paraphrased from his 1985 interview on pages 111 and 112 of The Playboy Interviews: Movers and Shakers.

When Steve Jobs got back from visting India, he thought about the most important thing he'd learned. It was that "Western rational thought is not innate". It is learned. It had never occured to Steve that if no one taught us how to think this way, we wouldn't. But that's how it is.

Steve Jobs says that to give away a dollar effectively is harder than to make a dollar. He argues this by saying that to learn you have to fail sometimes. And to fail, you have to have a measurement system so you know if you failed. You can give someone money to do something and most of the time you'll never find out if you succeeded or failed in your judgment of that person and his ideas and implementation. If you can't fail or succeed, then it's really hard to get better.

Reminds me of Popper. It has the core idea that we learn by trial and error. And it says that criticism is critically important to learning. Steve says it's hard to learn anything when it's hard to find out you were wrong. Being faced with your mistakes is crucial. The first statement about Western ways of thinking being learned is also something Popper knew, cared, and wrote about. Popper knew that other cultures had other ways of thinking (but that we can overcome these differences and learn from each other), and Popper also studied how Western thought started (before that time, no one anywhere thought this way).

http://www.blupete.com/Literature/Essays/Hazlitt/SpiritAge/Godwin.htm

The fault, then, of Mr. Godwin's philosophy, in one word, was too much ambition -- 'by that sin fell the angels!' He conceived too nobly of his fellows (the most unpardonable crime against them, for there is nothing that annoys our self-love so much as being complimented on imaginary achievements, to which we are wholly unequal)--he raised the standard of morality above the reach of humanity, and by directing virtue to the most airy and romantic heights, made her path dangerous, solitary, and impracticable. The author of the Political Justice took abstract reason for the rule of conduct and abstract good for its end. He places the human mind on an elevation, from which it commands a view of the whole line of moral consequences, and requires it to conform its acts to the larger and more enlightened conscience which it has thus acquired. He absolves man from the gross and narrow ties of sense, custom, authority, private and local attachment, in order that he may devote himself to the boundless pursuit of universal benevolence.

Mr. Godwin gives no quarter to the amiable weaknesses of our nature, nor does he stoop to avail himself of the supplementary aids of an imperfect virtue. Gratitude, promises, friendship, family affection give way, not that they may be merged in the opposite vices or in want of principle, but that the void may be filled up by the disinterested love of good and the dictates of inflexible justice, which is ' the law of laws, and sovereign of sovereigns.' All minor considerations yield, in his system, to the stern sense of duty, as they do, in the ordinary and established ones, to the voice of necessity. Mr. Godwin's theory, and that of more approved reasoners, differ only in this, that what are with them the exceptions, the extreme cases, he makes the every-day rule. No one denies that on great occasions, in moments of fearful excitement, or when a mighty object is at stake, the lesser and merely instrumental points of duty are to be sacrificed without remorse at the shrine of patriotism, of honour, and of conscience.

William Godwin by Elton Edward Smith and Esther Greenwell Smith, page 20:

as a child of the Enlightenment, in whom theological dogma had softened to moral philosophy and Biblical revelation had been domesticated into the controlling power of Reason, Godwin tended to think first of man and mind and only latterly of God and the Church.

The World of Parmenides, by Karl Popper, page 124:

what Freud might have described as a neurosis -- as a rejection of what Freud called the 'reality principle'. By the way, I am not a Freudian, and I even think that Freud's description of the world of the human mind may indeed be regarded as largely due to a convention or invention -- a very influence convention indeed.

Every rational discussion, that is, every discussion devoted to the search for truth, is based on principles, which in actual fact are ethical principles. I should like to share three of them.

• 1 The principle of fallibility. Perhaps I am wrong and perhaps you are right; but, of course, we may both be wrong.
• 2 The principle of rational discussion. We need to test critically and, of course, as impersonally as possible the various (criticizable) theories that are in dispute.
• 3 The principle of approximation to truth. We can nearly always come closer to the truth with the help of such critical discussions; and we can nearly always improve our understanding, even in cases where we do not reach agreement.

It is remarkable that these principles are epistemological and, at the same time, also ethical principles. For they imply, among other things, toleration: if I can learn from you, and if I want to learn, then in the interest of truth I have not only to tolerate you but also to recognize you as a potential equal; the potential unity of man and the potential equality of all humans are prerequisites for our willingness to discuss matters rationally. Of further importance is the principle that we can learn from a discussion, even when it does not lead to agreement. For a rational discussion can help to shed light upon some of our errors.

All this shows that ethical principles form the basis of science. The most important of all such ethical principles is the principle that objective truth is the fundamental regulative idea of all rational discussion. Further ethical principles embody our commitment to the search for truth and the idea of approximation to truth; and the importance of intellectual integrity and of fallibility, which lead us to a self-critical attitude and to toleration. It is also very important that we can learn in the field of ethics.

Karl Popper, The World of Parmenides, chapt 2, section 6, paragraph 5

See also chapt 2 Addendum 2 titled: Some Principles for a New Professional Ethics Based on Xenophanes' Theory of Truth

OSE volume 1 page 57:

the need to distinguish between two different elements in man's environment--his natural environment and his social environment. This is a distinction which is difficult to make and to grasp, as can be inferred from the fact that even now it is not clearly established in our minds ... Most of us, it seems, have a strong inclination to accept the peculiarities of our social environment as if they were 'natural'.

It is one of the characteristics of the magical attitude of a primitive tribal or 'closed' society that it lives in a charmed circle of unchanging taboos, of laws and customs which are felt to be as inevitable as the rising of the sun, or the cycle of the seasons, or similar obvious regularities of nature. And it is only after this magical 'closed society' has actually broken down that a theoretical understanding of the difference between 'nature' and 'society' can develop.

OSE volume 2 pages 89-90:

I am developing a view to which I subscribe myself ... the problem of the so-called rules of exogamy, i.e. the problem of explaining the wide distribution, among the most diverse cultures, of marriage laws apparently designed to prevent inbreeding ... [J.S.] Mill [and others] ... would try to explain these rules by an appeal to 'human nature' ... and something like this would also be the naive or popular explanation ... however, one could ask whether it is not the other way round ... whether the apparent instinct is not rather a product of education, the effect rather than the cause of the social rules and traditions demanding exogamy and forbidding incest ... [in this case] it would be difficult to determine which of the two theories is the correct one, the explanation of the traditional social rules by instinct or the explanation of an apparent instinct by traditional social rules ... [example where Karl Popper says experiments have shown that aversion to snakes, which was commonly thought to be instinct, is actually learned] ... This example should be taken as a warning. We are faced here with an aversion which is apparently universal, even beyond the human race ... The universal occurrence of a certain behavior is not a decisive argument in favour of its instinctive character, or of its being rooted in 'human nature'.

Here are two theories of how people make decisions.

One theory -- weighted decision making -- says that there are many factors that go into a decision. Each factor is given a weighting proportional to its importance, so it's not one vote per factor but rather the more important factors count for more. Then all the factors are added up, and the decision with the most support is made.

In this model, genes could have an influence in a decision for one side or another, and a 10% weighting, and thus would have some influence, and would sometimes tip the scales in close decisions. They could have a 50% influence in another type of decisions, and 90% in another. An environment could have different percent influence for each, and so on. Dozens of factors could be included. In general, there is no serious difficulty in proposing there's one more factor with a small weighting

In this model, the theory that genes have an influence, varying from 0% to 99%, and averaging around 50%, is plausible. It doesn't contradict anything about the model.

The second theory -- explanatory decision making -- says that decisions are made by conjecturing a set of possible decisions, and then criticizing each possibility. If only one possibility remains, that decision is made. If more than one remains, that is a significant problem (omitting details for brevity, just understand that this is considered a rare case). How options are ruled out does not depend on weighting the importance of anything. It is an all or nothing proposition -- either the option survives a criticism or it doesn't. (The only way it's not all-or-nothing is that we might propose a variant of an option which changes a few things in order to survive the criticism.)

In this model, we never add anything up to get a result. Nothing ever outweighs something else. Rather we always find a single explanation of why we think our decision is the best one.

In this model, the way to influence the decision making process is to offer conjectures, explanations and criticism. That takes thought, or pre-existing relevant knowledge. And influences are never 10% or 50%. Rather they are good ideas that are accepted (or accepted with minor changes) or they are bad ideas that are rejected in full.

In this model, the theory that genes have an influence on decisions, averaging around 50%, is incoherent. It's incompatible with this model. The only time genes could have an influence is when they encode ideas which could be considered in the decision making process, and then accepted or rejected on their merits (the result would be exactly the same if the idea came from a friend or a gene -- it depends entirely on what the idea is).