Intervention effects visible in many natural languages have been a lively issue in the syntactic and semantic literature in the last decade, starting with the seminal work by Beck (1996) and followed by a number of equally influential analyses. This paper highlights the limitations of some of these studies and proposes a reanalysis of intervention effects in terms of head movement. This paper also suggests an alternative Wh-movement approach for some Wh in-situ languages that show intervention effects, and claims that the nature of Wh-movement in natural languages has a direct consequence on the nature of Wh-quantifier interactions. I discuss data from various languages, particularly Hindi, English and Chinese to show how the nature of Wh-movement in these languages determines the presence of intervention effects as well as island effects. In this exploration, the paper also investigates the nature of constraints that regulate movement in these languages.