The Toffees have performed well below expectations this season, and they currently sit in 12th place in the Premier League table.
One of the major reasons behind this has been Roberto Martinez’s side’s inability to shut opposition sides out.
And Stoke City midfielder Adam feels that Everton need to start showing a greater willingness to defend, if they are to be successful in the future.
"On a personal note, I think they’re too open," the Scotland international said. "They play great football, but they ship too many goals.
"And I know it looks boring, but I think some of the Everton fans would like to go back to winning 1-0.
"Yeah, they have got great talent, but they have to find the solution to stop shipping goals."
Roberto Martinez’s positon as Everton boss is now under great scrutiny, and the Spaniard was not helped by comments that Leighton Baines made earlier in the week.
Baines suggested that Everton’s squad lack chemistry, and Sky Sports pundit Matt Le Tissier found himself agreeing with the left-back.
"It appears that way [there’s a lack of chemistry]," Le Tissier added. "If you look at the talent which is in that Everton side they should be doing better than what they are. They have the third worst home record in the Premier League and he’s looking at that thinking that they don’t have a strong team spirit. The results bear that out.
"Everton at home used to be a strong outfit, but now [it’s different]."
Everton’s next match comes against Watford at Vicarage Road on Saturday. A victory would take the Merseyside club up to 11th place in the top flight standings.