I worked under lot of bosses in my career. Some were obvious jerks, under whom I didn't enjoy working (though I now realise that maybe it wasn't their fault, it may have been the result of their conditioning), but a select few were a delight to work for. And over the course of my career I used to compare my bosses and tried to pin point reasons why I enjoyed working under some. There were many reasons like empathy, sense of humour, inherent niceness, competency, getting their hands dirty etc but the biggest reason was that they were highly ethical. Or I would say smart & ethical. And it wasn't only me almost all my colleagues enjoyed working under them and excelled in their performance.
Now I also understand the scientific reasons why it was so. Neuroscientifically our limbic brain continuously analyses threats in the environment, to help us survive (pl. click on the link to an earlier article for more details about this here- link). So we are wired to avoid threats/ painful situations and approach rewards or pleasing situations. And our inclination to avoid threat or painful situation is 10 times stronger than inclination to approach reward or pleasurable situation. In extreme cases it prepares us for the fight or flight response. When the threat perception is lower it puts us in mild threatening state where we are constantly on the lookout for threats and our attention is focussed on uncovering the hidden danger. Now brain can give energy to only one part at a time. Either to the limbic brain for our protection or to the prefrontal brain (the thinking brain). So in a mild threatening state our rational ability as well as subtler abilities like creativity, ability to connect the dots etc goes down. Also it strengthens our logical filters (as explained here - link). Or in other words we take everything with a pinch of salt. Don't you agree. Think of the last time when a person whom you don't rate very highly gave you some useful advice but you rejected it as you didn't value the person. But you accepted the same advise given by another person whom you respected more. In the former case your stronger defence mechanism acted as a barrier but in the latter case your defences were lowered and you accepted the advise.Thats why parents get some body really elderly who is respected by their teenage kid for career or other advise. Same advise by parents may get rejected but coming from the respected elder might get accepted. Same goes with the respected leaders. We feel less threatened dealing with them and as result our logical filters or defence mechanisms are lowered and we take in their advice.
But what makes a leader respected. Everything else being equal it's their ethical behaviour. And how does it make a difference. By not threatening our five social drivers.

First is our Status - So they don't shout at us in public or berate us or make fun of us in front of others. Neuroscientifically being shouted at in public is as bad as being threatened with a gun. Infact they make it a point of giving public praise, more opportunities to learn or other behaviours which enhance our social status.
Second is Certainty- They don't keep all the information closer to their chest. E.g. they share information about the reasons for company policies as much as they can. One of my respected bosses used to regularly share our vertical's financial report and had to actually educate us to make us understand it. It required an effort for him but it made us understand the reason behind company policies and we felt protected. Even if they don't have the answers right away they'll share a date by when they'll be able to provide clarity. Some of my bosses had very unpredictable behaviour and I could never be certain about their reactions and thus would always be in a threatening state. And though I performed reasonably well under them I could not match my performance under the respected bosses.
Third is Autonomy- When asked what to do, when to do, how to do, we feel constrained, as we are wired to have some autonomy in our life. Good bosses follow a three part system of defining goals, process and regular communication. But they keep the process part fluid and depending upon the situation might behave as a Counsellor (asking questions about problem), Mentor (Telling how to achieve solution) or a Coach (asking right questions so that we arrive the solution ourselves) and sometimes rarely also as manager - telling what, when, how to do. This kind of behaviour gives a sense of autonomy and we don't feel threatened with such bosses. They tolerate failure and know that by allowing us to make our own mistakes they are making us grow.
Fourth is Belonging - or knowing. Opposite of feeling lonely. Maybe that's why meeting strangers is threatening and alcohol helps fraternising easier. We like going to same restaurants as we are familiar with the surroundings there. Now think of the last time you were all alone at a party. I am sure you did not enjoy the evening one bit. In the office scenario being excluded from discussions, meetings puts us in the same threatening state and good bosses make it a point to include everyone.
And the last is Fairness - They are transparent and you know that they don't have favourites. And they don't threaten us.

So where do ethics come in. Above mentioned patterns of behaviour look easy to copy. But it’s actually not so. Unless a person is ethical the behaviour will come out as phony and the team will feel even more threatened. Simply because our behaviour is based on our beliefs and conditioning. Unless we are ethical it’s difficult to hide. Our limbic brain continuously scans the environment 5 times in a second and stores the information without we being even consciously aware of it. So when somebody is trying to act a behaviour as against actually living it he/she gives some small signs which can be read by others. E.g. Impatience - he will not let the other person finish but interrupt in between, start yawning and other negative body language. Or he may try showing his smartness by catching flaws, try to win the argument by proving other person wrong and so on.
That’s why sometimes we are uncomfortable with somebody without any obvious reasons. Girls whose limbic brain works better and the communication between the limbic brain and the prefrontal cortex is also keener seem to know better whether a person is trustworthy or not, as they can catch these subtle signs better.
And this is where ethics come in unless we are ethical we don’t respect the other person as we don’t think of them as our equal, don’t believe that he/she can improve, don’t empathise with them and they don’t feel connected to us.
As Mr Steven covey also says in his book 7 habits of highly effective people, unless one changes internally first one can’t change others. I have seen this all my life with my colleagues and bosses. One of my colleagues used to spend a lot of time studying literature on how to manipulate others and though initially seemed to be rising faster, had a middling career later on. Another of my boss used to talk very sweetly and would regularly give beer parties but his team members would quit after some time as they would realise his manipulative intentions.
The point is unless one is ethical it all comes out slowly. Thus one needs to work on oneself. Ultimately the only person one can change in this world is oneself and when one successfully does so the entire world changes.
How can one do it. There are easy and simple mind techniques to change our self-limiting beliefs and conditioned behaviour.