  Numerical simulations predict that the spin-down rate of a single
rotation-powered neutron star depends on the angle $\alpha$ between its spin
and magnetic axes as $P\dot P \propto \mu^2 (k_0 + k_1\sin^2\alpha)$, where $P$
is the star spin period, $\mu$ is its magnetic moment, while $k_0 \sim k_1 \sim
1$. Here we describe a simple observational test for this prediction based on
the comparison of spin-down rates of 50 nearly orthogonal (with $\alpha$ close
to 90 deg) and 27 nearly aligned (with $\alpha$ close to 0 deg) pulsars. We
found, that the apparent pulsar spin-down is consistent with the theory if
assumed, that magnetic moments of orthogonal rotators are systematically larger
than those of aligned ones for $\sim 0.15..0.2$ dex. Also, as a by-product of
the analysis, we provide yet another constraint on the average braking index of
radio pulsars as $1 \le n \le 4$ with formal significance not worse than 99\%.
