Why do my objects move when I don't want them?


I am very new to Blender, trying to figure out the basics based on guides and tutorials, but I have a problem I can’t seem to figure out:

Sometimes when I select an object and move it around in the interactive editor, some other, supposedly unrelated object moves in the same direction, but with a slower speed.

I am currently experimenting with physics and the game engine, but this has happened to objects which are not “connected” (by constraints or other means) to other objects. For example once I have just created a new light, selected it, started to move it, and the other light in the scene started to move in the same direction. (at a slower speed) None of them were involved in any kind of physics or animation. (or at least I didn’t set up anything)

Why does this happen?

thank you for any help!

(I have v2.54 on win 7)

You may have proportional editing on. Toggle it on/off with the letter O. There is a symbol on the 3d view header like a small circle that indicates it is on.

You are right, I had it switched on. Awesome.

Thank you very much!