Jean-Claude, the French manager appointed by the Western investor to head the sales team of a joint venture in Romania, was experiencing resistance from the sales managers reporting to him. Results were below target and Jean-Claude put the blame squarely on the sales force.

The board asked me to look into what was going wrong, and my first move was to attend Jean-Claude’s weekly meeting with the managers. It took about five minutes to pinpoint the problem.

Although Jean-Claude was polite and proper enough in what he said to his people, the expression on his face while he was talking made it seem if he was sipping lemon juice without sugar. How he gave the message was completely obliterating what he was saying.

Chatting afterwards to Ioanna, one of the sales managers, confirmed my guess. “The way he looks at us makes it clear he would place no value on anything we said,” she observed. “Why would anyone risk speaking up?”

When I met Jean-Claude next day again, I alerted him to the problem as politely and delicately as I could. He was astonished and thanked me for the warning. And at his next meeting he tried valiantly to moderate the impact of his sour appearance by smiling a few times and even cracked a joke.

But it was difficult for him to keep it up and he needed a certain amount of coaching, which I tried to give over the course of the several months I was monitoring the company. As I worked with him I gradually realized that his sour expression was to some extent a reflection of a lack of self-confidence and, by indicating and emphasizing his strong points, I tried to help him to trust himself more, which was helpful.

I also advised him to incorporate habit-breaking into his personal goals and that this required a concrete plan, identifying specific verbal and non-verbal behaviors to track. These included positive behaviors, such as smiling or saying thank you, and negative ones that caused problems, such as interrupting or looking at a cell-phone. He also tracked his emotional reactions when a negative behaviour occurred—did he feel angry, for instance, or suspicious, or let down, or humiliated?

For the next three months he kept a formal log. He drew up a kind of table listing them in the three categories: positive behaviors that improved an interaction with others, negative behaviors that thwarted interactions, and emotions associated with the negative behaviors. He carried the log around with him and after every encounter would review the list and tick off the behaviors and emotions that he had displayed or experienced. Every couple of weeks, when I was in the office, we would sit down and review the log.

Keeping a systematic record of these behaviors and emotions in this way and sharing the records with me helped to make Jean Claude more naturally self-aware, which translated into much greater self-control. As the log showed, he gradually but steadily came to display the positive behaviors more often than the negative ones.

I also kept an eye on his progress by periodically turning up at his meetings and by chatting to people about their experience of him. Within just a few weeks of starting the diary, the quality of feedback from the sales team and their engagement generally showed marked improvement. As Ioanna said to me over another coffee about six weeks into my work with Jean-Claude, “I hardly recognize the man.”

Transforming people is like that: little things like keeping a diary or tinkering with a routine make a huge difference and with no more than a nudge and a bit of encouragement you can achieve remarkable results.