Distortion in the whole mesh when applying scaling to a part I am new in blender. I am modelling a cup wherein I want to reduce the radius of the lower part. But when I select the lower circumference using Alt+ click and then press S to scale it down. the whole mesh get deformed as shown in the pictures. Can anybody help me where I am wrong?
Is it possible that you have enabled proportional editing with random pattern? 



You can disable it by click on the blue circle and selecting disable or by using the shortcut, o.