Lightweight, low cost, high density electrical connectors are disclosed that provide impedance controlled, high-speed, low interference communications, even in the absence of shields between the contacts, and that provide for a variety of other benefits not found in prior art connectors, such as low insertion loss. Signal contacts and ground contacts within the connectors can be scaled and positioned relative to one another such that a differential signal in a first differential signal pair produces a high field in the gap between the contacts that form the signal pair and a low field near an adjacent signal pair. Consequently, cross talk between adjacent signal contacts can be limited to acceptable levels for the particular application. In such connectors, the level of cross talk between adjacent signal contacts can be limited to the point that the need for (and cost of) shields between adjacent contacts is unnecessary, even in high speed, high signal integrity applications.