Strong
A strong level means other people's trouble genuinely moves you, including the trouble of people you will never meet. This is the warm channel, the one most people mean when they call someone empathetic, and it is the engine behind an enormous amount of unpaid work that holds families, friendships and neighbourhoods together. It has two costs worth naming. It is expensive when it runs without an accurate read — being moved to help while aiming at the wrong thing is tiring for everyone involved — and it is the channel people learn to use, because a reliable impulse to help is a reliable lever. Neither is a reason to want less of it; both are reasons to aim it.
Moderate
A moderate level means the pull is there and it is selective. Trouble close to you moves you; trouble at a distance registers and then recedes. That is the ordinary human setting, and it's the one most people are quietly relieved to find, because the top of this scale is expensive to run. The thing to watch is not the level itself but its distribution: for most people the boundary of concern follows the boundary of familiarity, and it is worth knowing where yours falls — because the people just outside it, the colleagues and acquaintances and the person two desks over, are the ones whose difficulty you will notice and then not act on.
Faint
A faint level here means other people's difficulties don't reliably pull at you — they register as facts rather than as things that demand something from you. The fair reading is that this channel measures the pull, not the behaviour: people at this level are often perfectly reliable when asked directly, and being unmoved by a story is not the same as refusing to help someone in front of you. What does tend to be true is that you don't volunteer, because the impulse that makes other people volunteer isn't firing. In work that involves distress at volume — medicine, emergency services, complaints, care — a low level on this channel is frequently what makes the work survivable rather than what makes someone bad at it.