Based on multiepoch observations at 15 and 43 GHz with the Very Long Baseli
ne Array (VLBA), we detect significant angular expansions between the two h
ot spots of four compact symmetric objects (CSOs). From these relative moti
ons we derive kinematic ages of between 300 and 1200 yr for the radio emiss
ion. These ages lend support to the idea that CSOs are produced in a recent
phase of activity. These observations also allow us to study the evolution
of the hot spots dynamically in individual sources. In ail four sources th
e hot spots are separating along the source axis, but in 1031 + 567 the tip
of the hot spot appears to be moving almost orthogonally to the source axi
s. Jet components, seen in three of the four sources observed, are found to
be moving relativistically outward from the central engines toward the mor
e slowly moving hot spots.