Lasswell – Hypodermic needle theory –

In this model, the media is seen as powerful and able to inject ideas into an audience who are seen as weak and passive.

The hypodermic needle was proposed by Harold Lasswell in the 1920s. It explains how the audience is directly affected by what they view and hear. It is said to affect the audience/viewer immediately or in the near future. 
It suggests that a media text can ‘inject’ or ‘fire’ ideas, values and attitudes into a passive audience, who might then act upon them. This theory suggests that the audience is powerless to resist the impact of the message which, in some cases, could be dangerous. 

Lasswell’s hypodermic model fits well in the case of Orson Welles’s ‘War of the World’, where listeners were passive, and accepted the information given to them despite the lack of evidence.

• “The War of the Worlds” was a Halloween episode of the radio series The Mercury Theatre on the Air directed and narrated by Orson Welles as an adaptation of H. G. Well’s novel The War of the Worlds (1898). It was performed and broadcast live at 8 pm ET on October 30, 1938, over the CBS Radio Network. The episode is famous for inciting panic by convincing some members of the listening audience that a Martian invasion was taking place, though the scale of panic is disputed, as the program had relatively few listeners.

• 12 million people listening was reported. More likely that just 50,000 people were listening.