The degree of peaking of the density profile has profound implications for reactor operation. As an independent complement to previous studies, density peaking in the JET tokamak was investigated on the most recent dataset, comprising virtually all experiments performed in 2006 and 2007. Unlike previous studies, this work focuses on low collisionality data as most representative of reactor conditions. The study confirms that collisionality is the most important parameter governing density peaking in H-mode, followed by the NBI particle flux and/or the Ti/Te temperature ratio. For the first time in JET a modest, albeit significant dependence of peaking on internal inductance, or magnetic shear is seen. The experimental behavior is compared to an extensive database of simulations based on linear gyrokinetic calculations using the GS2 code. The predictions from GS2 simulataions based on the highest linear growth rate modes are in good agreement with experimental observations. They are also corroborated by initial results from the non-linear code GYRO.