Are scientists of the mind different than other scientists?

Let me present three scenarios to you. I'll start with two that are pretty similar:

Scenario 1:
Once a week, every Tuesday, I go to a seminar on physics. Lots of people are in attendance. We have coffee, there's music, it's an awesome time. One or two speakers get up every week and talk about different topics in physics. The speakers talk about classical physics, Einsteinian physics, quantum physics, great topics. The speakers have no formal education in physics. Some of them had physics in high school though. They don't read physics journals, pay attention to physics in the media, and most of them have never read a book on physics. But they give entertaining, delightful lectures. Once I invited my friend, who is a graduate student in a physics program, to attend with me. He hated the lectures, and told me that everything I knew about physics was wrong! It was a bothersome experience for both of us. I still attend, but I don't talk about physics with my friend any more.

Scenario 2:
Once a week, every Friday, I go to a seminar on human behavior. Lots of people are in attendance. We have coffee, there's music, it's an awesome time. One or two speakers get up every week and talk about different topics in human relations and how to live a good life. The speakers talk about dealing with stress, relationships, being happy, great topics. The speakers have no formal education in human behavior. Some of them had psychology in high school though. They don't read psychology journals, pay attention to psychology in the media, and most of them have never read a book on psychology. But they give entertaining, delightful lectures. Once I invited my friend, who is a graduate student in a psychology program, to attend with me. He hated the lectures, and told me that everything I knew about human behavior was wrong! It was a bothersome experience for both of us. I still attend, but I don't talk about psychology with my friend any more.

I don't want to be a contentious scientist. But I do want to be a morally good person. I see it as a moral duty to tell someone when they have it wrong--the Sun goes around the Earth, you say? No, that's not how things are.

So this is why I'm presenting these scenarios. I encountered a situation the other day that I was extremely bothered by. It seems to me that there are certain situations in which people make the same bad choices repeatedly--but for some reason it never registers that those are bad choices. Let's examine Scenario 1 above. If, say, you are a layperson that takes advice from this ersatz physicist, it may not hurt you! You may never have to use quantum physics, so what's the harm? You may get bad advice from this person your whole life and never even realize it.

If, however, you plan on actually using physics and try to take the speaker's advice, things might get in trouble. You may, in fact, do some bad calculations and not even discover it. Maybe I'm taking his advice the wrong way, you'll say to yourself.

Things become even hairier in Scenario 2. Recall that the speakers here are talking about human nature and psychology, a science that lacks the precision often found in physics but a science nonetheless. Here it's a lot easier to convince yourself that maybe you are to blame. If an object falls faster than your "physics" predicts it will, you can go to your lecturer and say "Hey, what's up with your method? I used the acceleration of gravity as 13 meters per second per second just like you said!" Guess what? That's not gravity... so you might quickly realize that hey, it's probably a good idea to go to a different source than these crackpots who've never read a book on physics. So go talk to a physicist.

But in Scenario 2 (psychology), you might never reach that point of disillusion. You may say "Hey, I used your technique for reconciling with my wife, but she's still mad at me! What's up with your method?" He may respond, and you may be convinced, that you're just not doing it right. The only real way to know if it works or not is with the objective scientific method, which you're not going to hear from these guys--they don't read science books, after all. If it's not working, you might want to talk to a certified counselor or clinical psychologist.

The thing is, it's a lot easier to realize we're doing physics equations wrong than it is to realize we're going about human relations wrong. It seems less objective; it's harder to lose our subjectivity. Even for me, as a psychologist myself, I have that palm-slap moment almost every day where I think "You're a psychologist! How did you get tricked by that?!"

Let's move on to Scenario 3

Scenario 3:
Once a week, every Sunday, I go to Church. Lots of people are in attendance. We have coffee, there's music, it's an awesome time. One or two speakers get up every week and talk about different topics in human relations and how to live a good life. The speakers talk about dealing with stress, relationships, being happy, great topics. The speakers have no formal education in human behavior. Some of them had psychology in high school though. They don't read psychology journals, pay attention to psychology in the media, and most of them have never read a book on psychology. But they give entertaining, delightful lectures. Once I invited my friend, who is a graduate student in a psychology program, to attend with me. He hated the lectures, and told me that everything I knew about human behavior was wrong! It was a bothersome experience for both of us. I still attend Church, but I don't talk about psychology with my friend any more.

For some people reading this (if anyone reads this at all), this might be the step I lose you. In Scenario 1 (physics), I wanted you to come away with the feeling that the speakers were ridiculous--hopefully you felt that. In Scenario 2, as well, it's a little more difficult but you can tell that they are ridiculous. But logically, can we not make the progression to Scenario 3?

You might have a different experience than me, or a different interpretation than me, and I respect that. But when I go to a Church or religious activity, this is what I see. I see people telling me how to live a better life, how to deal with stress, how to relate to other human beings. I see them using techniques that have evolved with direct ancestors in techniques and lectures that were given 2000 years ago by early Christians and thousands of years before that by early Jews. I see them giving the same advice that is not based on evidence, does not come from psychology, is not as accurate as the advice of a specialist.

If someone was in the pulpit talking about physics, we'd call them crazy. Why do we let it slide if they are talking about human nature? For human nature does not have a science, it is called psychology, and it has made many strides since its formal inception little more than 100 years ago. In fact, many of the things we take as "common sense" today were discovered by psychology!

As I've studied the history of psychology, I've discovered many of the "duh, common sense" concepts I have as a child of the '80s were actually shocking when discovered by psychologists in the '70s and before! Psychology has done a lot of good, and psychologists are knowledgeable about human behavior. The best thing, in my opinion, is that they base their knowledge on the process of science.

This means that psychology 2000 years in the future will be necessarily radically different than psychology today. Human nature may not change that much, but our understanding of it will.

tl;dr: Argument from authority is a logical fallacy. The authority better know what he's talking about for me to trust him!