Lifetime measurements of yrast levels in ¹⁶²Yb and ¹⁶⁶Hf were performed using the recoil distance Doppler-shift method in coincidence mode. Excited states in ¹⁶²Yb and ¹⁶⁶Hf were populated via the reactions ¹¹⁶Cd(⁵⁰Ti, 4n) and ¹²²Sn(⁴⁸Ti, 4n), respectively. The resulting B(E2) values are compared with the X(5) critical point model predictions and interacting boson approximation (IBA) model calculations. The X(5) model provides a reasonable description of the yrast B(E2) values in ¹⁶⁶Hf, whereas the IBA fails to reproduce the transition strengths from the higher spin levels. In ¹⁶²Yb, some transitions agree with the X(5) predictions while others are more consistent with the predictions of the IBA or a deformed symmetric rotor.